Address PR feedback

src/Compilers/CSharp/Portable/Operations/CSharpOperationFactory_Methods.cs

@@ -193,7 +193,7 @@ private ImmutableArray<IOperation> GetAnonymousObjectCreationInitializers(BoundA
                 SyntaxNode syntax = value.Syntax?.Parent ?? expression.Syntax;
                 ITypeSymbol type = target.Type;
                 Optional<object> constantValue = value.ConstantValue;
-                var assignment = new SimpleAssignmentExpression(target, value, _semanticModel, syntax, type, constantValue, isImplicit: false);
+                var assignment = new SimpleAssignmentExpression(target, value, _semanticModel, syntax, type, constantValue, isImplicit: expression.WasCompilerGenerated);
                 builder.Add(assignment);
             }
 

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

@@ -1610,6 +1610,65 @@ public static void Main()
 }", additionalRefs: new[] { SystemCoreRef }).VerifyDiagnostics();
         }
 
+        [CompilerTrait(CompilerFeature.IOperation)]
+        [Fact]
+        public void AnonymousTypeSymbols_ErrorCases()
+        {
+            string source = @"
+class ClassA
+{
+    static void Test1(int x)
+    {
+        var obj = /*<bind>*/new { f1 = null, f2 = M, f3 = default }/*</bind>*/;
+    }
+
+    static void M()
+    {
+    }
+}
+";
+            string expectedOperationTree = @"
+IAnonymousObjectCreationOperation (OperationKind.AnonymousObjectCreation, Type: <anonymous type: error f1, error f2, error f3>, IsInvalid) (Syntax: 'new { f1 =  ... = default }')
+  Initializers(3):
+      ISimpleAssignmentOperation (OperationKind.SimpleAssignment, Type: error, Constant: null, IsInvalid) (Syntax: 'f1 = null')
+        Left: 
+          IPropertyReferenceOperation: error <anonymous type: error f1, error f2, error f3>.f1 { get; } (OperationKind.PropertyReference, Type: error, IsInvalid) (Syntax: 'f1')
+            Instance Receiver: 
+              null
+        Right: 
+          ILiteralOperation (OperationKind.Literal, Type: null, Constant: null, IsInvalid) (Syntax: 'null')
+      ISimpleAssignmentOperation (OperationKind.SimpleAssignment, Type: error, IsInvalid) (Syntax: 'f2 = M')
+        Left: 
+          IPropertyReferenceOperation: error <anonymous type: error f1, error f2, error f3>.f2 { get; } (OperationKind.PropertyReference, Type: error, IsInvalid) (Syntax: 'f2')
+            Instance Receiver: 
+              null
+        Right: 
+          IOperation:  (OperationKind.None, Type: null, IsInvalid) (Syntax: 'M')
+            Children(1):
+                IInstanceReferenceOperation (OperationKind.InstanceReference, Type: ClassA, IsInvalid, IsImplicit) (Syntax: 'M')
+      ISimpleAssignmentOperation (OperationKind.SimpleAssignment, Type: error, IsInvalid) (Syntax: 'f3 = default')
+        Left: 
+          IPropertyReferenceOperation: error <anonymous type: error f1, error f2, error f3>.f3 { get; } (OperationKind.PropertyReference, Type: error, IsInvalid) (Syntax: 'f3')
+            Instance Receiver: 
+              null
+        Right: 
+          IDefaultValueOperation (OperationKind.DefaultValue, Type: null, IsInvalid) (Syntax: 'default')
+";
+            var expectedDiagnostics = new DiagnosticDescription[] {
+                // file.cs(6,35): error CS0828: Cannot assign '<null>' to anonymous type property
+                //         var obj = /*<bind>*/new { f1 = null, f2 = M, f3 = default }/*</bind>*/;
+                Diagnostic(ErrorCode.ERR_AnonymousTypePropertyAssignedBadValue, "f1 = null").WithArguments("<null>").WithLocation(6, 35),
+                // file.cs(6,46): error CS0828: Cannot assign 'method group' to anonymous type property
+                //         var obj = /*<bind>*/new { f1 = null, f2 = M, f3 = default }/*</bind>*/;
+                Diagnostic(ErrorCode.ERR_AnonymousTypePropertyAssignedBadValue, "f2 = M").WithArguments("method group").WithLocation(6, 46),
+                // file.cs(6,54): error CS0828: Cannot assign 'default' to anonymous type property
+                //         var obj = /*<bind>*/new { f1 = null, f2 = M, f3 = default }/*</bind>*/;
+                Diagnostic(ErrorCode.ERR_AnonymousTypePropertyAssignedBadValue, "f3 = default").WithArguments("default").WithLocation(6, 54)
+            };
+
+            VerifyOperationTreeAndDiagnosticsForTest<AnonymousObjectCreationExpressionSyntax>(source, expectedOperationTree, expectedDiagnostics);
+        }
+
         #region "Utility methods"
 
         private void AssertCannotConstruct(ISymbol type)

src/Compilers/VisualBasic/Portable/Operations/VisualBasicOperationFactory_Methods.vb

@@ -207,7 +207,7 @@ Namespace Microsoft.CodeAnalysis.Operations
                 Dim syntax As SyntaxNode = If(value.Syntax?.Parent, expression.Syntax)
                 Dim type As ITypeSymbol = target.Type
                 Dim constantValue As [Optional](Of Object) = value.ConstantValue
-                Dim assignment = New SimpleAssignmentExpression(target, value, _semanticModel, syntax, type, constantValue, isImplicit:=False)
+                Dim assignment = New SimpleAssignmentExpression(target, value, _semanticModel, syntax, type, constantValue, isImplicit:=expression.WasCompilerGenerated)
                 builder.Add(assignment)
             Next i