Work around unexpected value assertion

Currently AssertIsClosureScopeSyntax is failing for an interpolated string syntax
within particular expression appearing in Analyzer Runner. This change works around
the issue by using simple string concatenation instead.

src/Tools/AnalyzerRunner/Options.cs

@@ -118,8 +118,8 @@ internal static Options Create(string[] args)
                         else
                         {
                             throw new InvalidDataException((arg.StartsWith("/", StringComparison.Ordinal) ?
-                             $"Unrecognized option {arg}" :
-                             $"Unrecognized parameter {arg}"));
+                             "Unrecognized option " + arg :
+                             "Unrecognized parameter " + arg));
                         }
                         break;
                 }