Add hoisted catch exception to the local scope

src/Compilers/CSharp/Test/Emit/PDB/PDBAsyncTests.cs

@@ -1470,6 +1470,7 @@ .maxstack  3
         <forward declaringType=""C"" methodName=""F"" />
         <hoistedLocalScopes>
           <slot startOffset=""0xe"" endOffset=""0xed"" />
+          <slot startOffset=""0x29"" endOffset=""0x32"" />
         </hoistedLocalScopes>
         <encLocalSlotMap>
           <slot kind=""27"" offset=""0"" />

src/Compilers/VisualBasic/Portable/CodeGen/EmitStatement.vb

@@ -344,6 +344,12 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.CodeGen
                         Case BoundKind.FieldAccess
                             Dim left = DirectCast(exceptionSource, BoundFieldAccess)
                             If Not left.FieldSymbol.IsShared Then
+
+                                Dim stateMachineField = TryCast(left.FieldSymbol, StateMachineFieldSymbol)
+                                If (stateMachineField IsNot Nothing) AndAlso (stateMachineField.SlotIndex >= 0) Then
+                                    DefineUserDefinedStateMachineHoistedLocal(stateMachineField)
+                                End If
+
                                 ' When assigning to a field
                                 ' we need to push param address below the exception
                                 Dim temp = AllocateTemp(exceptionSource.Type, exceptionSource.Syntax)
@@ -1414,17 +1420,21 @@ OtherExpressions:
             '  817                  // we skip loading this lifted field since it is out of scope.
 
             For Each field In scope.Fields
-                Dim name As String = Nothing
-                Dim index As Integer = 0
-                Dim parsedOk As Boolean = GeneratedNames.TryParseStateMachineHoistedUserVariableName(field.Name, name, index)
-                Debug.Assert(parsedOk)
-                Debug.Assert(index >= 0)
-                If parsedOk Then
+                DefineUserDefinedStateMachineHoistedLocal(DirectCast(field, StateMachineFieldSymbol))
+            Next
+
+            EmitStatement(scope.Statement)
+
+            _builder.CloseLocalScope()
+        End Sub
+
+        Private Sub DefineUserDefinedStateMachineHoistedLocal(field As StateMachineFieldSymbol)
+            Debug.Assert(field.SlotIndex >= 0)
             Dim fakePdbOnlyLocal = New LocalDefinition(
                         symbolOpt:=Nothing,
                         nameOpt:=field.Name,
                         type:=Nothing,
-                        slot:=index,
+                        slot:=field.SlotIndex,
                         synthesizedKind:=SynthesizedLocalKind.EmitterTemp,
                         id:=Nothing,
                         pdbAttributes:=Cci.PdbWriter.DefaultLocalAttributesValue,
@@ -1432,12 +1442,6 @@ OtherExpressions:
                         isDynamic:=False,
                         dynamicTransformFlags:=Nothing)
             _builder.AddLocalToScope(fakePdbOnlyLocal)
-                End If
-            Next
-
-            EmitStatement(scope.Statement)
-
-            _builder.CloseLocalScope()
         End Sub
 
         Private Sub EmitUnstructuredExceptionResumeSwitch(node As BoundUnstructuredExceptionResumeSwitch)

src/Compilers/VisualBasic/Portable/Lowering/StateMachineRewriter/StateMachineFieldSymbol.vb

 ' Copyright (c) Microsoft.  All Rights Reserved.  Licensed under the Apache License, Version 2.0.  See License.txt in the project root for license information.
 
-Imports Microsoft.Cci
 Imports Microsoft.CodeAnalysis.CodeGen
-Imports Microsoft.CodeAnalysis.Text
 Imports Microsoft.CodeAnalysis.VisualBasic.Symbols
-Imports Microsoft.CodeAnalysis.VisualBasic.Syntax
 
 Namespace Microsoft.CodeAnalysis.VisualBasic
 
     ''' <summary>
     ''' Represents a synthesized state machine helper field.
     ''' </summary>
-    Friend Class StateMachineFieldSymbol
+    Friend NotInheritable Class StateMachineFieldSymbol
         Inherits SynthesizedFieldSymbol
         Implements ISynthesizedMethodBodyImplementationSymbol