unmark a parameter as processed by ConvertArg in case named parameters will be used

Author: Timur Kelman

CodeConverter/CSharp/ExpressionNodeVisitor.cs

@@ -1739,6 +1739,7 @@ async Task<ArgumentSyntax> ConvertArg(VBSyntax.ArgumentSyntax arg, int argIndex)
             if (arg.IsOmitted) {
                 if (invocationSymbol != null && !invocationHasOverloads) {
                     forceNamedParameters = true;
+                    processedParameters.Remove(parameterSymbol?.Name);
                     return null; //Prefer to skip omitted and use named parameters when the symbol has only one overload
                 }