Add well-known types/members for async iterators, add reference for ValueTask (#27100)

build/Targets/Packages.props

@@ -33,7 +33,7 @@
     <MicrosoftCodeAnalysisCSharpWorkspacesVersion>1.0.1</MicrosoftCodeAnalysisCSharpWorkspacesVersion>
     <MicrosoftCodeAnalysisEditorFeaturesTextVersion>1.0.1</MicrosoftCodeAnalysisEditorFeaturesTextVersion>
     <MicrosoftCodeAnalysisElfieVersion>0.10.6</MicrosoftCodeAnalysisElfieVersion>
-    <MicrosoftCodeAnalysisTestResourcesProprietaryVersion>2.0.7</MicrosoftCodeAnalysisTestResourcesProprietaryVersion>
+    <MicrosoftCodeAnalysisTestResourcesProprietaryVersion>2.0.9</MicrosoftCodeAnalysisTestResourcesProprietaryVersion>
     <MicrosoftCodeAnalysisVisualBasicVersion>1.0.1</MicrosoftCodeAnalysisVisualBasicVersion>
     <MicrosoftCodeAnalysisVisualBasicWorkspacesVersion>1.0.1</MicrosoftCodeAnalysisVisualBasicWorkspacesVersion>
     <MicrosoftCodeAnalysisWorkspacesCommonVersion>1.0.1</MicrosoftCodeAnalysisWorkspacesCommonVersion>

src/Compilers/CSharp/Portable/Symbols/Compilation_WellKnownMembers.cs

@@ -975,6 +975,11 @@ protected override bool IsByRefMethod(MethodSymbol method)
                 return method.RefKind != RefKind.None;
             }
 
+            protected override bool IsByRefProperty(PropertySymbol property)
+            {
+                return property.RefKind != RefKind.None;
+            }
+
             protected override bool IsGenericMethodTypeParam(TypeSymbol type, int paramPosition)
             {
                 if (type.Kind != SymbolKind.TypeParameter)

src/Compilers/CSharp/Test/Emit/CodeGen/CodeGenAsyncIteratorTests.cs

+// Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
+
+using System.Linq;
+using Microsoft.CodeAnalysis.CSharp.Syntax;
+using Microsoft.CodeAnalysis.CSharp.Test.Utilities;
+using Microsoft.CodeAnalysis.Test.Utilities;
+using Xunit;
+
+namespace Microsoft.CodeAnalysis.CSharp.UnitTests.CodeGen
+{
+    [CompilerTrait(CompilerFeature.AsyncStreams)]
+    public class CodeGenAsyncIteratorTests : EmitMetadataTestBase
+    {
+        // PROTOTYPE(async-streams): Consider moving this common test code to TestSources.cs
+        private static readonly string s_common = @"
+namespace System.Collections.Generic
+{
+    public interface IAsyncEnumerable<out T>
+    {
+        IAsyncEnumerator<T> GetAsyncEnumerator();
+    }
+
+    public interface IAsyncEnumerator<out T> : System.IAsyncDisposable
+    {
+        System.Threading.Tasks.Task<bool> WaitForNextAsync();
+        T TryGetNext(out bool success);
+    }
+}
+namespace System
+{
+    public interface IAsyncDisposable
+    {
+        System.Threading.Tasks.Task DisposeAsync();
+    }
+}
+
+namespace System.Runtime.CompilerServices
+{
+    public interface IStrongBox<T>
+    {
+        ref T Value { get; }
+    }
+}
+
+namespace System.Threading.Tasks
+{
+    using System.Runtime.CompilerServices;
+    using System.Threading.Tasks.Sources;
+
+    public struct ManualResetValueTaskSourceLogic<TResult>
+    {
+        public ManualResetValueTaskSourceLogic(IStrongBox<ManualResetValueTaskSourceLogic<TResult>> parent)
+        {
+        }
+
+        public short Version
+            => throw null;
+
+        public ValueTaskSourceStatus GetStatus(short token)
+            => throw null;
+
+        public TResult GetResult(short token)
+            => throw null;
+
+        public void Reset()
+            => throw null;
+
+        public void OnCompleted(Action<object> continuation, object state, short token, ValueTaskSourceOnCompletedFlags flags)
+            => throw null;
+
+        public void SetResult(TResult result)
+            => throw null;
+
+        public void SetException(Exception error)
+            => throw null;
+    }
+}
+";
+
+        [Fact]
+        public void TestWellKnownMembers()
+        {
+            var comp = CreateCompilation(s_common, references: new[] { TestReferences.NetStandard20.TasksExtensionsRef }, targetFramework: Roslyn.Test.Utilities.TargetFramework.NetStandard20);
+            comp.VerifyDiagnostics();
+
+            verifyType(WellKnownType.System_Runtime_CompilerServices_IStrongBox_T,
+                "System.Runtime.CompilerServices.IStrongBox<T>");
+
+            verifyMember(WellKnownMember.System_Runtime_CompilerServices_IStrongBox_T__Value,
+                "ref T System.Runtime.CompilerServices.IStrongBox<T>.Value { get; }");
+
+            verifyMember(WellKnownMember.System_Runtime_CompilerServices_IStrongBox_T__get_Value,
+                "ref T System.Runtime.CompilerServices.IStrongBox<T>.Value.get");
+
+            verifyType(WellKnownType.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T,
+                "System.Threading.Tasks.ManualResetValueTaskSourceLogic<TResult>");
+
+            verifyMember(WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__ctor,
+                "System.Threading.Tasks.ManualResetValueTaskSourceLogic<TResult>..ctor(System.Runtime.CompilerServices.IStrongBox<System.Threading.Tasks.ManualResetValueTaskSourceLogic<TResult>> parent)");
+
+            verifyMember(WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__GetResult,
+                "TResult System.Threading.Tasks.ManualResetValueTaskSourceLogic<TResult>.GetResult(System.Int16 token)");
+
+            verifyMember(WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__GetStatus,
+                "System.Threading.Tasks.Sources.ValueTaskSourceStatus System.Threading.Tasks.ManualResetValueTaskSourceLogic<TResult>.GetStatus(System.Int16 token)");
+
+            verifyMember(WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__OnCompleted,
+                "void System.Threading.Tasks.ManualResetValueTaskSourceLogic<TResult>.OnCompleted(System.Action<System.Object> continuation, System.Object state, System.Int16 token, System.Threading.Tasks.Sources.ValueTaskSourceOnCompletedFlags flags)");
+
+            verifyMember(WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__Reset,
+                "void System.Threading.Tasks.ManualResetValueTaskSourceLogic<TResult>.Reset()");
+
+            verifyMember(WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__SetResult,
+                "void System.Threading.Tasks.ManualResetValueTaskSourceLogic<TResult>.SetResult(TResult result)");
+
+            verifyMember(WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__get_Version,
+                "System.Int16 System.Threading.Tasks.ManualResetValueTaskSourceLogic<TResult>.Version.get");
+
+            verifyType(WellKnownType.System_Threading_Tasks_Sources_ValueTaskSourceStatus,
+                "System.Threading.Tasks.Sources.ValueTaskSourceStatus");
+
+            verifyType(WellKnownType.System_Threading_Tasks_Sources_ValueTaskSourceOnCompletedFlags,
+                "System.Threading.Tasks.Sources.ValueTaskSourceOnCompletedFlags");
+
+            verifyType(WellKnownType.System_Threading_Tasks_Sources_IValueTaskSource_T,
+                "System.Threading.Tasks.Sources.IValueTaskSource<out TResult>");
+
+            verifyMember(WellKnownMember.System_Threading_Tasks_Sources_IValueTaskSource_T__GetResult,
+                "TResult System.Threading.Tasks.Sources.IValueTaskSource<out TResult>.GetResult(System.Int16 token)");
+
+            verifyMember(WellKnownMember.System_Threading_Tasks_Sources_IValueTaskSource_T__GetStatus,
+                "System.Threading.Tasks.Sources.ValueTaskSourceStatus System.Threading.Tasks.Sources.IValueTaskSource<out TResult>.GetStatus(System.Int16 token)");
+
+            verifyMember(WellKnownMember.System_Threading_Tasks_Sources_IValueTaskSource_T__OnCompleted,
+                "void System.Threading.Tasks.Sources.IValueTaskSource<out TResult>.OnCompleted(System.Action<System.Object> continuation, System.Object state, System.Int16 token, System.Threading.Tasks.Sources.ValueTaskSourceOnCompletedFlags flags)");
+
+            verifyType(WellKnownType.System_Threading_Tasks_ValueTask_T,
+                "System.Threading.Tasks.ValueTask<TResult>");
+
+            verifyMember(WellKnownMember.System_Threading_Tasks_ValueTask_T__ctor,
+                "System.Threading.Tasks.ValueTask<TResult>..ctor(System.Threading.Tasks.Sources.IValueTaskSource<TResult> source, System.Int16 token)");
+
+            void verifyType(WellKnownType type, string expected)
+            {
+                var symbol = comp.GetWellKnownType(type);
+                Assert.Equal(expected, symbol.ToTestDisplayString());
+            }
+
+            void verifyMember(WellKnownMember member, string expected)
+            {
+                var symbol = comp.GetWellKnownTypeMember(member);
+                Assert.Equal(expected, symbol.ToTestDisplayString());
+            }
+        }
+    }
+}

src/Compilers/CSharp/Test/Symbol/Symbols/MissingSpecialMember.cs

@@ -566,6 +566,12 @@ public void AllWellKnownTypes()
                     case WellKnownType.System_IAsyncDisposable:
                     case WellKnownType.System_Collections_Generic_IAsyncEnumerable_T:
                     case WellKnownType.System_Collections_Generic_IAsyncEnumerator_T:
+                    case WellKnownType.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T:
+                    case WellKnownType.System_Runtime_CompilerServices_IStrongBox_T:
+                    case WellKnownType.System_Threading_Tasks_Sources_ValueTaskSourceStatus:
+                    case WellKnownType.System_Threading_Tasks_Sources_ValueTaskSourceOnCompletedFlags:
+                    case WellKnownType.System_Threading_Tasks_Sources_IValueTaskSource_T:
+                    case WellKnownType.System_Threading_Tasks_ValueTask_T:
                     // Not yet in the platform.
                     case WellKnownType.Microsoft_CodeAnalysis_Runtime_Instrumentation:
                         // Not always available.
@@ -874,6 +880,20 @@ public void AllWellKnownTypeMembers()
                     case WellKnownMember.System_Collections_Generic_IAsyncEnumerable_T__GetAsyncEnumerator:
                     case WellKnownMember.System_Collections_Generic_IAsyncEnumerator_T__TryGetNext:
                     case WellKnownMember.System_Collections_Generic_IAsyncEnumerator_T__WaitForNextAsync:
+                    case WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__ctor:
+                    case WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__get_Version:
+                    case WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__GetResult:
+                    case WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__GetStatus:
+                    case WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__OnCompleted:
+                    case WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__Reset:
+                    case WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__SetResult:
+                    case WellKnownMember.System_Runtime_CompilerServices_IStrongBox_T__Value:
+                    case WellKnownMember.System_Runtime_CompilerServices_IStrongBox_T__get_Value:
+                    case WellKnownMember.System_Threading_Tasks_Sources_IValueTaskSource_T__GetResult:
+                    case WellKnownMember.System_Threading_Tasks_Sources_IValueTaskSource_T__GetStatus:
+                    case WellKnownMember.System_Threading_Tasks_Sources_IValueTaskSource_T__OnCompleted:
+                    case WellKnownMember.System_Threading_Tasks_ValueTask_T__ctor:
+
                         // Not yet in the platform.
                         continue;
                     case WellKnownMember.Microsoft_CodeAnalysis_Runtime_Instrumentation__CreatePayloadForMethodsSpanningSingleFile:

src/Compilers/Core/Portable/SignatureComparer.cs

@@ -53,6 +53,12 @@ public bool MatchPropertySignature(PropertySymbol property, ImmutableArray<byte>
                 return false;
             }
 
+            bool isByRef = IsByRef(signature, ref position);
+            if (IsByRefProperty(property) != isByRef)
+            {
+                return false;
+            }
+
             // get the property type
             if (!MatchType(GetPropertyType(property), signature, ref position))
             {
@@ -287,6 +293,7 @@ private static short ReadTypeId(ImmutableArray<byte> signature, ref int position
 
         protected abstract bool IsByRefParam(ParameterSymbol parameter);
         protected abstract bool IsByRefMethod(MethodSymbol method);
+        protected abstract bool IsByRefProperty(PropertySymbol property);
 
         protected abstract TypeSymbol GetFieldType(FieldSymbol field);
     }

src/Compilers/Core/Portable/WellKnownMember.cs

@@ -447,6 +447,20 @@ internal enum WellKnownMember
         System_Collections_Generic_IAsyncEnumerator_T__WaitForNextAsync,
         System_Collections_Generic_IAsyncEnumerator_T__TryGetNext,
 
+        System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__ctor,
+        System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__GetResult,
+        System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__GetStatus,
+        System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__OnCompleted,
+        System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__Reset,
+        System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__SetResult,
+        System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__get_Version,
+        System_Runtime_CompilerServices_IStrongBox_T__Value,
+        System_Runtime_CompilerServices_IStrongBox_T__get_Value,
+        System_Threading_Tasks_Sources_IValueTaskSource_T__GetResult,
+        System_Threading_Tasks_Sources_IValueTaskSource_T__GetStatus,
+        System_Threading_Tasks_Sources_IValueTaskSource_T__OnCompleted,
+        System_Threading_Tasks_ValueTask_T__ctor,
+
         Count
     }
 }

src/Compilers/Core/Portable/WellKnownTypes.cs

@@ -279,6 +279,12 @@ internal enum WellKnownType
         System_IAsyncDisposable,
         System_Collections_Generic_IAsyncEnumerable_T,
         System_Collections_Generic_IAsyncEnumerator_T,
+        System_Threading_Tasks_ManualResetValueTaskSourceLogic_T,
+        System_Runtime_CompilerServices_IStrongBox_T,
+        System_Threading_Tasks_Sources_ValueTaskSourceStatus,
+        System_Threading_Tasks_Sources_ValueTaskSourceOnCompletedFlags,
+        System_Threading_Tasks_Sources_IValueTaskSource_T,
+        System_Threading_Tasks_ValueTask_T,
 
         NextAvailable,
     }
@@ -553,6 +559,12 @@ internal static class WellKnownTypes
             "System.IAsyncDisposable",
             "System.Collections.Generic.IAsyncEnumerable`1",
             "System.Collections.Generic.IAsyncEnumerator`1",
+            "System.Threading.Tasks.ManualResetValueTaskSourceLogic`1",
+            "System.Runtime.CompilerServices.IStrongBox`1",
+            "System.Threading.Tasks.Sources.ValueTaskSourceStatus",
+            "System.Threading.Tasks.Sources.ValueTaskSourceOnCompletedFlags",
+            "System.Threading.Tasks.Sources.IValueTaskSource`1",
+            "System.Threading.Tasks.ValueTask`1",
         };
 
         private readonly static Dictionary<string, WellKnownType> s_nameToTypeIdMap = new Dictionary<string, WellKnownType>((int)Count);

src/Compilers/VisualBasic/Portable/Symbols/WellKnownMembers.vb

@@ -628,6 +628,10 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
                 Return method.ReturnsByRef
             End Function
 
+            Protected Overrides Function IsByRefProperty(ByVal [property] As PropertySymbol) As Boolean
+                Return [property].ReturnsByRef
+            End Function
+
             Protected Overrides Function IsGenericMethodTypeParam(type As TypeSymbol, paramPosition As Integer) As Boolean
                 If type.Kind <> SymbolKind.TypeParameter Then
                     Return False

src/Compilers/VisualBasic/Test/Symbol/SymbolsTests/WellKnownTypeValidationTests.vb

@@ -506,7 +506,13 @@ End Namespace
                          WellKnownType.System_ReadOnlySpan_T,
                          WellKnownType.System_IAsyncDisposable,
                          WellKnownType.System_Collections_Generic_IAsyncEnumerable_T,
-                         WellKnownType.System_Collections_Generic_IAsyncEnumerator_T
+                         WellKnownType.System_Collections_Generic_IAsyncEnumerator_T,
+                         WellKnownType.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T,
+                         WellKnownType.System_Runtime_CompilerServices_IStrongBox_T,
+                         WellKnownType.System_Threading_Tasks_Sources_ValueTaskSourceStatus,
+                         WellKnownType.System_Threading_Tasks_Sources_ValueTaskSourceOnCompletedFlags,
+                         WellKnownType.System_Threading_Tasks_Sources_IValueTaskSource_T,
+                         WellKnownType.System_Threading_Tasks_ValueTask_T
                         ' Not available on all platforms.
                         Continue For
                     Case WellKnownType.ExtSentinel
@@ -550,7 +556,13 @@ End Namespace
                          WellKnownType.System_ReadOnlySpan_T,
                          WellKnownType.System_IAsyncDisposable,
                          WellKnownType.System_Collections_Generic_IAsyncEnumerable_T,
-                         WellKnownType.System_Collections_Generic_IAsyncEnumerator_T
+                         WellKnownType.System_Collections_Generic_IAsyncEnumerator_T,
+                         WellKnownType.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T,
+                         WellKnownType.System_Runtime_CompilerServices_IStrongBox_T,
+                         WellKnownType.System_Threading_Tasks_Sources_ValueTaskSourceStatus,
+                         WellKnownType.System_Threading_Tasks_Sources_ValueTaskSourceOnCompletedFlags,
+                         WellKnownType.System_Threading_Tasks_Sources_IValueTaskSource_T,
+                         WellKnownType.System_Threading_Tasks_ValueTask_T
                         ' Not available on all platforms.
                         Continue For
                     Case WellKnownType.ExtSentinel
@@ -604,7 +616,20 @@ End Namespace
                          WellKnownMember.System_IAsyncDisposable__DisposeAsync,
                          WellKnownMember.System_Collections_Generic_IAsyncEnumerable_T__GetAsyncEnumerator,
                          WellKnownMember.System_Collections_Generic_IAsyncEnumerator_T__TryGetNext,
-                         WellKnownMember.System_Collections_Generic_IAsyncEnumerator_T__WaitForNextAsync
+                         WellKnownMember.System_Collections_Generic_IAsyncEnumerator_T__WaitForNextAsync,
+                         WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__ctor,
+                         WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__get_Version,
+                         WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__GetResult,
+                         WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__GetStatus,
+                         WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__OnCompleted,
+                         WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__Reset,
+                         WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__SetResult,
+                         WellKnownMember.System_Runtime_CompilerServices_IStrongBox_T__Value,
+                         WellKnownMember.System_Runtime_CompilerServices_IStrongBox_T__get_Value,
+                         WellKnownMember.System_Threading_Tasks_Sources_IValueTaskSource_T__GetResult,
+                         WellKnownMember.System_Threading_Tasks_Sources_IValueTaskSource_T__GetStatus,
+                         WellKnownMember.System_Threading_Tasks_Sources_IValueTaskSource_T__OnCompleted,
+                         WellKnownMember.System_Threading_Tasks_ValueTask_T__ctor
                         ' Not available yet, but will be in upcoming release.
                         Continue For
                     Case WellKnownMember.Microsoft_CodeAnalysis_Runtime_Instrumentation__CreatePayloadForMethodsSpanningSingleFile,
@@ -702,7 +727,20 @@ End Namespace
                          WellKnownMember.System_IAsyncDisposable__DisposeAsync,
                          WellKnownMember.System_Collections_Generic_IAsyncEnumerable_T__GetAsyncEnumerator,
                          WellKnownMember.System_Collections_Generic_IAsyncEnumerator_T__TryGetNext,
-                         WellKnownMember.System_Collections_Generic_IAsyncEnumerator_T__WaitForNextAsync
+                         WellKnownMember.System_Collections_Generic_IAsyncEnumerator_T__WaitForNextAsync,
+                         WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__ctor,
+                         WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__get_Version,
+                         WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__GetResult,
+                         WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__GetStatus,
+                         WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__OnCompleted,
+                         WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__Reset,
+                         WellKnownMember.System_Threading_Tasks_ManualResetValueTaskSourceLogic_T__SetResult,
+                         WellKnownMember.System_Runtime_CompilerServices_IStrongBox_T__Value,
+                         WellKnownMember.System_Runtime_CompilerServices_IStrongBox_T__get_Value,
+                         WellKnownMember.System_Threading_Tasks_Sources_IValueTaskSource_T__GetResult,
+                         WellKnownMember.System_Threading_Tasks_Sources_IValueTaskSource_T__GetStatus,
+                         WellKnownMember.System_Threading_Tasks_Sources_IValueTaskSource_T__OnCompleted,
+                         WellKnownMember.System_Threading_Tasks_ValueTask_T__ctor
                         ' Not available yet, but will be in upcoming release.
                         Continue For
                     Case WellKnownMember.Microsoft_CodeAnalysis_Runtime_Instrumentation__CreatePayloadForMethodsSpanningSingleFile,

src/Test/Utilities/Portable/Mocks/TestReferences.cs

@@ -260,6 +260,11 @@ public static class NetStandard20
         () => AssemblyMetadata.CreateFromImage(TestResources.NetFX.netstandard20.Microsoft_CSharp).GetReference(display: "Microsoft.CSharp.dll (netstandard 2.0 ref)"),
         LazyThreadSafetyMode.PublicationOnly);
         public static PortableExecutableReference MicrosoftCSharpRef => s_microsoftCSharp.Value;
+
+        private static readonly Lazy<PortableExecutableReference> s_system_Threading_Tasks_Extensions = new Lazy<PortableExecutableReference>(
+        () => AssemblyMetadata.CreateFromImage(TestResources.NetFX.netstandard20.System_Threading_Tasks_Extensions).GetReference(display: "System.Threading.Tasks.Extensions.dll (netstandard 2.0)"),
+        LazyThreadSafetyMode.PublicationOnly);
+        public static PortableExecutableReference TasksExtensionsRef => s_system_Threading_Tasks_Extensions.Value;
     }
 
     public static class DiagnosticTests