Address review comments

src/Compilers/CSharp/Test/Semantic/IOperation/IOperationTests_IArgument.cs

@@ -2245,7 +2245,7 @@ static void M2(int x)
             var invocation = (IInvocationExpression)operation;
             var argument = invocation.ArgumentsInEvaluationOrder[0];
 
-            // We are calling VB extension methods on IArgument in C# code, therefore exception is expteced here.
+            // We are calling VB extension methods on IArgument in C# code, therefore exception is expected here.
             Assert.Throws<ArgumentException>(() => argument.GetInConversion());
             Assert.Throws<ArgumentException>(() => argument.GetOutConversion());
         }

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

@@ -106,7 +106,6 @@ Namespace Microsoft.CodeAnalysis.Semantics
                 Case Else
                     Dim lastParameterIndex = parameters.Length - 1
                     Dim kind As ArgumentKind
-                    Dim parameter As ParameterSymbol
 
                     If index = lastParameterIndex AndAlso ParameterIsParamArray(parameters(lastParameterIndex)) Then
                         ' TODO: figure out if this is true:
@@ -114,21 +113,19 @@ Namespace Microsoft.CodeAnalysis.Semantics
                         '       a list of arguments (including 0 argument) is provided for ParamArray parameter in source
                         '       https://github.com/dotnet/roslyn/issues/18550
                         kind = If(argument.WasCompilerGenerated AndAlso argument.Kind = BoundKind.ArrayCreation, ArgumentKind.ParamArray, ArgumentKind.Explicit)
-                        parameter = parameters(lastParameterIndex)
                     Else
                         ' TODO: figure our if this is true:
                         '       a compiler generated argument for an Optional parameter is created iff
                         '       the argument is omitted from the source
                         '       https://github.com/dotnet/roslyn/issues/18550
                         kind = If(argument.WasCompilerGenerated, ArgumentKind.DefaultValue, ArgumentKind.Explicit)
-                        parameter = parameters(index)
                     End If
                     
                     Dim value = Create(argument)
                     Return New VisualBasicArgument(
                         kind,
-                        parameter,
-                        Create(argument),
+                        parameters(index),
+                        value,
                         inConversion:=New Conversion(Conversions.Identity),
                         outConversion:=New Conversion(Conversions.Identity),
                         semanticModel:=_semanticModel,