[Bug target/94194] x86: Provide feraiseexcept builtins

[joseph at codesourcery dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94194

--- Comment #3 from joseph at codesourcery dot com <joseph at codesourcery dot com> ---
GCC already has implicit knowledge of how FE_* for exceptions relate to 
the hardware, because it generates calls to __atomic_feraiseexcept, which 
is defined in libatomic using FE_* from <fenv.h>.  I think SPARC Solaris 
is the only case where this actually turned out to be OS-specific (see 
SPARC_LOW_FE_EXCEPT_VALUES).