[libc] Re-Enable GPU tests and fix math exception handling (#83172)

Summary:
A lot of these tests failed previously and were disabled. However we
have fixed some things since then and many of these seem to pass.
Additionally, the last remaining math tests that failed seemed to be due
to the exception handling. For now we just set it to be 'errno'.

These pass locally when tested on a gfx1030, gfx90a, and sm_89
architecture. Hopefully these pass correctly on the sm_60 bot as I've
had things fail on that one only before.