C++ avoid warning in visual studio build due to clang specific directive

The revently added clang directive cause a new warning for Visual Studio build. Need to include the new code with a directive checking for visual studio

runtime/Cpp/runtime/src/support/CPPUtils.cpp

@@ -50,8 +50,10 @@ namespace antlrcpp {
             break;
           }
           // else fall through
+#ifndef _MSC_VER
 #if __has_cpp_attribute(clang::fallthrough)
           [[clang::fallthrough]];
+#endif
 #endif
 
         default: