Remove CallerArgumentExpression feature flag

src/Compilers/VisualBasic/Portable/Binding/Binder_Invocation.vb

@@ -3126,11 +3126,6 @@ ProduceBoundNode:
 
                     Dim isCallerArgumentExpression = callerArgumentExpressionParameterIndex > -1 OrElse (reducedExtensionReceiverOpt IsNot Nothing AndAlso callerArgumentExpressionParameterIndex > -2)
 
-                    If isCallerArgumentExpression AndAlso Not SyntaxTree.Options.Features.ContainsKey(InternalSyntax.GetFeatureFlag(InternalSyntax.Feature.CallerArgumentExpression)) Then
-                        ' Silently require feature flag for this feature until Aleksey approves.
-                        isCallerArgumentExpression = False
-                    End If
-
                     If isCallerLineNumber OrElse isCallerMemberName OrElse isCallerFilePath OrElse isCallerArgumentExpression Then
                         Dim callerInfoValue As ConstantValue = Nothing
 

src/Compilers/VisualBasic/Portable/Parser/ParserFeature.vb

@@ -41,15 +41,12 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Syntax.InternalSyntax
         UnconstrainedTypeParameterInConditional
         CommentsAfterLineContinuation
         InitOnlySettersUsage
-        CallerArgumentExpression
     End Enum
 
     Friend Module FeatureExtensions
         <Extension>
         Friend Function GetFeatureFlag(feature As Feature) As String
             Select Case feature
-                Case Feature.CallerArgumentExpression
-                    Return NameOf(Feature.CallerArgumentExpression)
                 Case Else
                     Return Nothing
             End Select
@@ -181,8 +178,6 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Syntax.InternalSyntax
                     Return ERRID.FEATURE_CommentsAfterLineContinuation
                 Case Feature.InitOnlySettersUsage
                     Return ERRID.FEATURE_InitOnlySettersUsage
-                Case Feature.CallerArgumentExpression
-                    Return ERRID.FEATURE_CallerArgumentExpression
                 Case Else
                     Throw ExceptionUtilities.UnexpectedValue(feature)
             End Select

src/Compilers/VisualBasic/Portable/Symbols/Source/SourceComplexParameterSymbol.vb

@@ -249,11 +249,6 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols
 
         Friend Overrides ReadOnly Property CallerArgumentExpressionParameterIndex As Integer
             Get
-                If Not _syntaxRef.SyntaxTree.Options.Features.ContainsKey(InternalSyntax.GetFeatureFlag(InternalSyntax.Feature.CallerArgumentExpression)) Then
-                    ' Silently require feature flag for this feature until Aleksey approves.
-                    Return -1
-                End If
-
                 Dim attributeSource As SourceParameterSymbol = If(Me.BoundAttributesSource, Me)
 
                 Dim data = attributeSource.GetEarlyDecodedWellKnownAttributeData()

src/Compilers/VisualBasic/Portable/Symbols/Source/SourceParameterSymbol.vb

@@ -242,8 +242,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols
                 arguments.GetOrCreateData(Of ParameterEarlyWellKnownAttributeData).HasCallerFilePathAttribute = True
             ElseIf VisualBasicAttributeData.IsTargetEarlyAttribute(arguments.AttributeType, arguments.AttributeSyntax, AttributeDescription.CallerMemberNameAttribute) Then
                 arguments.GetOrCreateData(Of ParameterEarlyWellKnownAttributeData).HasCallerMemberNameAttribute = True
-            ElseIf VisualBasicAttributeData.IsTargetEarlyAttribute(arguments.AttributeType, arguments.AttributeSyntax, AttributeDescription.CallerArgumentExpressionAttribute) AndAlso
-                Location.SourceTree.Options.Features.ContainsKey(InternalSyntax.GetFeatureFlag(InternalSyntax.Feature.CallerArgumentExpression)) Then
+            ElseIf VisualBasicAttributeData.IsTargetEarlyAttribute(arguments.AttributeType, arguments.AttributeSyntax, AttributeDescription.CallerArgumentExpressionAttribute) Then
                 Dim index = -1
                 Dim attribute = arguments.Binder.GetAttribute(arguments.AttributeSyntax, arguments.AttributeType, False)
                 If Not attribute.HasErrors Then
@@ -268,15 +267,6 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols
         Friend Overrides Iterator Function GetCustomAttributesToEmit(compilationState As ModuleCompilationState) As IEnumerable(Of VisualBasicAttributeData)
             Dim attributes = MyBase.GetCustomAttributesToEmit(compilationState)
 
-            If Location Is Nothing OrElse Not Location.IsInSource OrElse
-                Not Location.SourceTree.Options.Features.ContainsKey(InternalSyntax.GetFeatureFlag(InternalSyntax.Feature.CallerArgumentExpression)) Then
-                ' Silently require feature flag for this feature until Aleksey approves.
-                For Each attribute In attributes
-                    Yield attribute
-                Next
-                Return
-            End If
-
             For Each attribute In attributes
                 If AttributeData.IsTargetEarlyAttribute(attributeType:=attribute.AttributeClass, attributeArgCount:=attribute.CommonConstructorArguments.Length, description:=AttributeDescription.CallerArgumentExpressionAttribute) Then
                     Dim callerArgumentExpressionParameterIndex = Me.CallerArgumentExpressionParameterIndex
@@ -368,8 +358,7 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols
                 arguments.GetOrCreateData(Of CommonParameterWellKnownAttributeData)().HasOutAttribute = True
             ElseIf attrData.IsTargetAttribute(Me, AttributeDescription.MarshalAsAttribute) Then
                 MarshalAsAttributeDecoder(Of CommonParameterWellKnownAttributeData, AttributeSyntax, VisualBasicAttributeData, AttributeLocation).Decode(arguments, AttributeTargets.Parameter, MessageProvider.Instance)
-            ElseIf attrData.IsTargetAttribute(Me, AttributeDescription.CallerArgumentExpressionAttribute) AndAlso
-                Location.SourceTree.Options.Features.ContainsKey(InternalSyntax.GetFeatureFlag(InternalSyntax.Feature.CallerArgumentExpression)) Then
+            ElseIf attrData.IsTargetAttribute(Me, AttributeDescription.CallerArgumentExpressionAttribute) Then
                 Dim index = GetEarlyDecodedWellKnownAttributeData()?.CallerArgumentExpressionParameterIndex
                 If index = Ordinal Then
                     DirectCast(arguments.Diagnostics, BindingDiagnosticBag).Add(ERRID.WRN_CallerArgumentExpressionAttributeSelfReferential, arguments.AttributeSyntaxOpt.Location, Me.Name)

src/Compilers/VisualBasic/Portable/Symbols/Source/SourceSimpleParameterSymbol.vb

@@ -131,10 +131,6 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Symbols
 
         Friend Overrides ReadOnly Property CallerArgumentExpressionParameterIndex As Integer
             Get
-                If Not Location.SourceTree.Options.Features.ContainsKey(InternalSyntax.GetFeatureFlag(InternalSyntax.Feature.CallerArgumentExpression)) Then
-                    ' Silently require feature flag for this feature until Aleksey approves.
-                    Return -1
-                End If
                 Dim data = GetEarlyDecodedWellKnownAttributeData()
                 If data Is Nothing Then
                     Return -1

src/Compilers/VisualBasic/Test/Emit/Attributes/AttributeTests_CallerArgumentExpression.vb

@@ -35,7 +35,7 @@ End Module
         End Sub
 
         <ConditionalFact(GetType(CoreClrOnly))>
-        Public Sub TestGoodCallerArgumentExpressionAttribute_OldVersionWithFeatureFlag()
+        Public Sub TestGoodCallerArgumentExpressionAttribute_OldVersion()
             Dim source As String = "
 Imports System
 Imports System.Runtime.CompilerServices
@@ -51,7 +51,7 @@ Module Program
 End Module
 "
 
-            Dim compilation = CreateCompilation(source, targetFramework:=TargetFramework.NetCoreApp, references:={Net451.MicrosoftVisualBasic}, options:=TestOptions.ReleaseExe, parseOptions:=TestOptions.Regular16.WithFeature("CallerArgumentExpression"))
+            Dim compilation = CreateCompilation(source, targetFramework:=TargetFramework.NetCoreApp, references:={Net451.MicrosoftVisualBasic}, options:=TestOptions.ReleaseExe, parseOptions:=TestOptions.Regular16)
             CompileAndVerify(compilation, expectedOutput:="123").VerifyDiagnostics()
         End Sub
 
@@ -258,27 +258,6 @@ End Module
             CompileAndVerify(compilation, expectedOutput:="0 + 1").VerifyDiagnostics()
         End Sub
 
-        <ConditionalFact(GetType(CoreClrOnly))>
-        Public Sub TestGoodCallerArgumentExpressionAttribute_Version16_9_WithoutFeatureFlag()
-            Dim source As String = "
-Imports System
-Imports System.Runtime.CompilerServices
-Module Program
-    Sub Main()
-        Log(123)
-    End Sub
-
-    Private Const p As String = NameOf(p)
-    Sub Log(p As Integer, <CallerArgumentExpression(p)> Optional arg As String = ""<default-arg>"")
-        Console.WriteLine(arg)
-    End Sub
-End Module
-"
-
-            Dim compilation = CreateCompilation(source, targetFramework:=TargetFramework.NetCoreApp, references:={Net451.MicrosoftVisualBasic}, options:=TestOptions.ReleaseExe, parseOptions:=TestOptions.Regular16_9)
-            CompileAndVerify(compilation, expectedOutput:="<default-arg>").VerifyDiagnostics()
-        End Sub
-
         <ConditionalFact(GetType(CoreClrOnly))>
         Public Sub TestGoodCallerArgumentExpressionAttribute_ExpressionHasTrivia()
             Dim source = "