Since commit v3.3.0-rc1~397^2 (Check*CompilerFlag: Refactor method used
to pass flags, 2015-02-24) these check modules pass the flags to the
compiler front-end during linking as well as during compilation. This
breaks checks for flags like '-x c++' that are meant only for the
compilation step. Revert the change and add a test covering a
compiler-only flag.