The Intel C compiler for Linux does not seem to reject any bad flags or
object files on its link lines. Work around the problem by using a
preprocessor #error directive to ensure that BADFLAG appears in the
build output. This does not really achieve the purpose of the tests but
it allows them to pass.
Add a LinkFlags test series to check that these properties work. Since
no link flag is accepted everywhere we test for presence of flags by
adding a bad flag and looking for the complaint in the test output.