Revision r280064 adds new options -fdenormal-fp-math and passes through option

-ffast-math to CC1, but it included a wrong llvm regression tests which was
removed in r280065.  Although regression test noexceptionsfpmath.c makes sure
-fno-trapping-math ends up as a function attribute, this adds a test that
explicitly checks the driver output for -fno-trapping-math.

llvm-svn: 280227