fixes after merge

src/Compilers/CSharp/Portable/Binder/Binder_Symbols.cs

@@ -2075,21 +2075,25 @@ private AssemblySymbol GetForwardedToAssembly(string fullName, int arity, Diagno
 
         internal static bool CheckFeatureAvailability(SyntaxNode syntax, MessageID feature, DiagnosticBag diagnostics, Location locationOpt = null)
         {
-            CSDiagnosticInfo error = GetFeatureAvailabilityDiagnosticInfo(syntax, feature);
+            return CheckFeatureAvailability(syntax.SyntaxTree, feature, diagnostics, locationOpt ?? syntax.GetLocation());
+        }
+
+        internal static bool CheckFeatureAvailability(SyntaxTree tree, MessageID feature, DiagnosticBag diagnostics, Location location)
+        {
+            CSDiagnosticInfo error = GetFeatureAvailabilityDiagnosticInfo(tree, feature);
 
             if (error is null)
             {
                 return true;
             }
 
-            var location = locationOpt ?? syntax.GetLocation();
             diagnostics.Add(new CSDiagnostic(error, location));
             return false;
         }
 
         internal static bool CheckFeatureAvailability(SyntaxNode syntax, MessageID feature, ref HashSet<DiagnosticInfo> useSiteDiagnostics)
         {
-            CSDiagnosticInfo error = GetFeatureAvailabilityDiagnosticInfo(syntax, feature);
+            CSDiagnosticInfo error = GetFeatureAvailabilityDiagnosticInfo(syntax.SyntaxTree, feature);
 
             if (error is null)
             {
@@ -2100,9 +2104,9 @@ internal static bool CheckFeatureAvailability(SyntaxNode syntax, MessageID featu
             return false;
         }
 
-        private static CSDiagnosticInfo GetFeatureAvailabilityDiagnosticInfo(SyntaxNode syntax, MessageID feature)
+        private static CSDiagnosticInfo GetFeatureAvailabilityDiagnosticInfo(SyntaxTree tree, MessageID feature)
         {
-            CSharpParseOptions options = (CSharpParseOptions)syntax.SyntaxTree.Options;
+            CSharpParseOptions options = (CSharpParseOptions)tree.Options;
 
             if (options.IsFeatureEnabled(feature))
             {

src/Compilers/CSharp/Portable/BoundTree/Expression.cs

@@ -116,7 +116,7 @@ internal partial class BoundStackAllocArrayCreation
 
     internal partial class BoundConvertedStackAllocExpression
     {
-        protected override ImmutableArray<IOperation> Children => ImmutableArray.Create<IOperation>(this.Count);
+        protected override ImmutableArray<BoundNode> Children => ImmutableArray.Create<BoundNode>(this.Count);
     }
 
     internal partial class BoundDynamicObjectCreationExpression

src/Compilers/CSharp/Portable/Symbols/Source/SourceMemberMethodSymbol.cs

@@ -23,13 +23,11 @@ protected struct Flags
         {
             // We currently pack everything into a 32 bit int with the following layout:
             //
-            // |   |s|r|q|z|y|xxxxxxxxxxxxxxxxxxxxxx|wwwww|
+            // |   |s|r|q|z|xxxxxxxxxxxxxxxxxxxxxxx|wwwww|
             // 
             // w = method kind.  5 bits.
             //
-            // x = modifiers.  22 bits.
-            //
-            // y = returnsVoid. 1 bit.
+            // x = modifiers.  23 bits.
             //
             // z = isExtensionMethod. 1 bit.
             //
@@ -43,7 +41,7 @@ protected struct Flags
             private const int DeclarationModifiersOffset = 5;
 
             private const int MethodKindMask = 0x1F;
-            private const int DeclarationModifiersMask = 0x3FFFFF;
+            private const int DeclarationModifiersMask = 0x7FFFFF;
 
             private const int ReturnsVoidBit = 1 << 27;
             private const int IsExtensionMethodBit = 1 << 28;
@@ -52,11 +50,12 @@ protected struct Flags
             private const int IsMetadataVirtualLockedBit = 1 << 31;
 
             private int _flags;
+            private bool _returnsVoid;
 
             public bool ReturnsVoid
             {
-                get { return (_flags & ReturnsVoidBit) != 0; }
-                set { _flags = value ? (_flags | ReturnsVoidBit) : (_flags & ~ReturnsVoidBit); }
+                get { return _returnsVoid; }
+                set { _returnsVoid = value; }
             }
 
             public MethodKind MethodKind
@@ -115,12 +114,12 @@ private static bool ModifiersRequireMetadataVirtual(DeclarationModifiers modifie
 
                 int methodKindInt = ((int)methodKind & MethodKindMask) << MethodKindOffset;
                 int declarationModifiersInt = ((int)declarationModifiers & DeclarationModifiersMask) << DeclarationModifiersOffset;
-                int returnsVoidInt = returnsVoid ? ReturnsVoidBit : 0;
                 int isExtensionMethodInt = isExtensionMethod ? IsExtensionMethodBit : 0;
                 int isMetadataVirtualIgnoringInterfaceImplementationChangesInt = isMetadataVirtual ? IsMetadataVirtualIgnoringInterfaceChangesBit : 0;
                 int isMetadataVirtualInt = isMetadataVirtual ? IsMetadataVirtualBit : 0;
 
-                _flags = methodKindInt | declarationModifiersInt | returnsVoidInt | isExtensionMethodInt | isMetadataVirtualIgnoringInterfaceImplementationChangesInt | isMetadataVirtualInt;
+                _flags = methodKindInt | declarationModifiersInt | isExtensionMethodInt | isMetadataVirtualIgnoringInterfaceImplementationChangesInt | isMetadataVirtualInt;
+                _returnsVoid = returnsVoid;
             }
 
             public bool IsMetadataVirtual(bool ignoreInterfaceImplementationChanges = false)

src/Compilers/CSharp/Test/Semantic/Semantics/DynamicTests.cs

@@ -1264,9 +1264,9 @@ Type Arguments(0)
                 // file.cs(7,15): error CS1978: Cannot use an expression of type '__arglist' as an argument to a dynamically dispatched operation.
                 //         d.Goo(__arglist(123, 456));
                 Diagnostic(ErrorCode.ERR_BadDynamicMethodArg, "__arglist(123, 456)").WithArguments("__arglist").WithLocation(7, 15),
-                // file.cs(8,31): error CS1738: Named argument specifications must appear after all fixed arguments have been specified. Please use language version 7.2 or greater to allow non-trailing named arguments.
+                // file.cs(8,31): error CS8324: Named argument specifications must appear after all fixed arguments have been specified in a dynamic invocation.
                 //         d.Goo(x: 123, y: 456, 789);
-                Diagnostic(ErrorCode.ERR_NamedArgumentSpecificationBeforeFixedArgument, "789").WithArguments("7.2").WithLocation(8, 31),
+                Diagnostic(ErrorCode.ERR_NamedArgumentSpecificationBeforeFixedArgumentInDynamicInvocation, "789").WithLocation(8, 31),
                 // file.cs(10,25): error CS1978: Cannot use an expression of type 'void' as an argument to a dynamically dispatched operation.
                 //         /*<bind>*/d.Goo(System.Console.WriteLine());/*</bind>*/
                 Diagnostic(ErrorCode.ERR_BadDynamicMethodArg, "System.Console.WriteLine()").WithArguments("void").WithLocation(10, 25),