Address code review comments

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

@@ -494,6 +494,7 @@ IExpression IMemberReferenceExpression.Instance
        
         protected override OperationKind ExpressionKind => OperationKind.MethodBindingExpression;
 
+        // SyntaxNode for MethodBindingExpression is the argument of DelegateCreationExpression 
         SyntaxNode IOperation.Syntax => this.Argument.Syntax;
 
         public override void Accept(OperationVisitor visitor)

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

@@ -32,6 +32,7 @@ ImmutableArray<IStatement> IBlockStatement.Statements
         {
             get
             {
+                // This is to filter out operations of kind None.
                 return (ImmutableArray<IStatement>) s_blockStatementsMappings.GetValue(this,
                     blockStatement => { return blockStatement.Statements.AsImmutable<IStatement>().WhereAsArray(statement => statement.Kind != OperationKind.None); }
                     );

src/Compilers/Core/CodeAnalysisTest/Diagnostics/OperationTestAnalyzer.cs

@@ -1149,12 +1149,10 @@ public class LambdaTestAnalyzer : DiagnosticAnalyzer
             DiagnosticSeverity.Warning,
             isEnabledByDefault: true);
 
-        public sealed override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics
-        {
-            get { return ImmutableArray.Create(LambdaExpressionDescriptor, 
-                                                TooManyStatementsInLambdaExpressionDescriptor,
-                                                NoneOperationInLambdaExpressionDescriptor); }
-        }
+        public sealed override ImmutableArray<DiagnosticDescriptor> SupportedDiagnostics => 
+            ImmutableArray.Create(LambdaExpressionDescriptor, 
+                                  TooManyStatementsInLambdaExpressionDescriptor,
+                                  NoneOperationInLambdaExpressionDescriptor);
 
         public sealed override void Initialize(AnalysisContext context)
         {

src/Compilers/Core/Portable/Compilation/IOperationWalker.cs

@@ -12,13 +12,13 @@ public abstract class OperationWalker : OperationVisitor
     {
         private int _recursionDepth;
 
-        private void VisitList<T>(ImmutableArray<T> list) where T : IOperation
+        private void VisitArray<T>(ImmutableArray<T> list) where T : IOperation
         {
             if (!list.IsDefault)
             {
-                for (int i = 0; i < list.Length; i++)
+                foreach (var operation in list)
                 {
-                    Visit(list[i]);
+                    Visit(operation);
                 }
             }
         }
@@ -28,20 +28,27 @@ public override void Visit(IOperation operation)
             if (operation != null)
             {
                 _recursionDepth++;
-                StackGuard.EnsureSufficientExecutionStack(_recursionDepth);
-                operation.Accept(this);
-                _recursionDepth--;
+                try
+                {
+                    StackGuard.EnsureSufficientExecutionStack(_recursionDepth);
+                    operation.Accept(this);
+                }
+                finally
+                {
+                    _recursionDepth--;
+                }
+                
             }
         }
 
         public override void VisitBlockStatement(IBlockStatement operation)
         {
-            VisitList(operation.Statements);
+            VisitArray(operation.Statements);
         }
 
         public override void VisitVariableDeclarationStatement(IVariableDeclarationStatement operation)
         {
-            VisitList(operation.Variables);
+            VisitArray(operation.Variables);
         }
 
         public override void VisitVariable(IVariable operation)
@@ -52,13 +59,13 @@ public override void VisitVariable(IVariable operation)
         public override void VisitSwitchStatement(ISwitchStatement operation)
         {
             Visit(operation.Value);
-            VisitList(operation.Cases);
+            VisitArray(operation.Cases);
         }
 
         public override void VisitCase(ICase operation)
         {
-            VisitList(operation.Clauses);
-            VisitList(operation.Body);
+            VisitArray(operation.Clauses);
+            VisitArray(operation.Body);
         }
 
         public override void VisitSingleValueCaseClause(ISingleValueCaseClause operation)
@@ -100,10 +107,10 @@ public override void VisitWhileUntilLoopStatement(IWhileUntilLoopStatement opera
 
         public override void VisitForLoopStatement(IForLoopStatement operation)
         {
-            VisitList(operation.Before);
+            VisitArray(operation.Before);
             Visit(operation.Condition);
             Visit(operation.Body);
-            VisitList(operation.AtLoopBottom);
+            VisitArray(operation.AtLoopBottom);
         }
 
         public override void VisitForEachLoopStatement(IForEachLoopStatement operation)
@@ -148,7 +155,7 @@ public override void VisitLockStatement(ILockStatement operation)
         public override void VisitTryStatement(ITryStatement operation)
         {
             Visit(operation.Body);
-            VisitList(operation.Catches);
+            VisitArray(operation.Catches);
             Visit(operation.FinallyHandler);
         }
 
@@ -194,7 +201,7 @@ public override void VisitEndStatement(IStatement operation)
         public override void VisitInvocationExpression(IInvocationExpression operation)
         {
             Visit(operation.Instance);
-            VisitList(operation.ArgumentsInSourceOrder);
+            VisitArray(operation.ArgumentsInSourceOrder);
         }
 
         public override void VisitArgument(IArgument operation)
@@ -210,7 +217,7 @@ public override void VisitOmittedArgumentExpression(IExpression operation)
         public override void VisitArrayElementReferenceExpression(IArrayElementReferenceExpression operation)
         {
             Visit(operation.ArrayReference);
-            VisitList(operation.Indices);
+            VisitArray(operation.Indices);
         }
 
         public override void VisitPointerIndirectionReferenceExpression(IPointerIndirectionReferenceExpression operation)
@@ -318,8 +325,8 @@ public override void VisitAddressOfExpression(IAddressOfExpression operation)
 
         public override void VisitObjectCreationExpression(IObjectCreationExpression operation)
         {
-            VisitList(operation.ConstructorArguments);
-            VisitList(operation.MemberInitializers);
+            VisitArray(operation.ConstructorArguments);
+            VisitArray(operation.MemberInitializers);
         }
 
         public override void VisitFieldInitializer(IFieldInitializer operation)
@@ -339,13 +346,13 @@ public override void VisitParameterInitializer(IParameterInitializer operation)
 
         public override void VisitArrayCreationExpression(IArrayCreationExpression operation)
         {
-            VisitList(operation.DimensionSizes);
+            VisitArray(operation.DimensionSizes);
             Visit(operation.Initializer);
         }
 
         public override void VisitArrayInitializer(IArrayInitializer operation)
         {
-            VisitList(operation.ElementValues);
+            VisitArray(operation.ElementValues);
         }
 
         public override void VisitAssignmentExpression(IAssignmentExpression operation)

src/Compilers/VisualBasic/Portable/BoundTree/Statement.vb

@@ -851,6 +851,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic
 
         Private ReadOnly Property IStatements As ImmutableArray(Of IStatement) Implements IBlockStatement.Statements
             Get
+                ' This is to filter out operations of kind None.
                 Dim statements = s_blockStatementsMappings.GetValue(Me, Function(boundBlock)
                                                                             Return boundBlock.Statements.As(Of IStatement).WhereAsArray(Function(statement)
                                                                                                                                             Return statement.Kind <> OperationKind.None

src/Compilers/VisualBasic/Test/Semantic/Diagnostics/OperationAnalyzerTests.vb

@@ -1160,7 +1160,7 @@ End Class
             comp.VerifyAnalyzerDiagnostics({New MemberReferenceAnalyzer}, Nothing, Nothing, False,
                  Diagnostic(MemberReferenceAnalyzer.HandlerAddedDescriptor.Id, "AddHandler Mumble, New MumbleEventHandler(AddressOf Mumbler)").WithLocation(7, 9),
                  Diagnostic(MemberReferenceAnalyzer.MethodBindingDescriptor.Id, "AddressOf Mumbler").WithLocation(7, 51),
-                 Diagnostic("HandlerAdded", "AddHandler Mumble, New MumbleEventHandler(Sub(s As Object, a As System.EventArgs)
+                 Diagnostic(MemberReferenceAnalyzer.HandlerAddedDescriptor.Id, "AddHandler Mumble, New MumbleEventHandler(Sub(s As Object, a As System.EventArgs)
                                                   End Sub)").WithLocation(8, 9),
                  Diagnostic(MemberReferenceAnalyzer.FieldReferenceDescriptor.Id, "Mumble").WithLocation(10, 20),
                  Diagnostic(MemberReferenceAnalyzer.MethodBindingDescriptor.Id, "AddressOf Mumbler").WithLocation(12, 39),