Partially handled MSVC system headers after VS 2015 Update 3.

The rest of the fix requires an update to Clang.

Signed-off-by: Dimitar Dobrev <dpldobrev@protonmail.com>

src/CppParser/Parser.cpp

@@ -274,7 +274,7 @@ void Parser::SetupHeader()
         args.push_back("-std=gnu++98");
         break;
     default:
-        args.push_back("-std=gnu++11");
+        args.push_back(Opts->MicrosoftMode ? "-std=gnu++14" : "-std=gnu++11");
         break;
     }
     args.push_back("-fno-rtti");