x86: Remove feraiseexcept optimization

Similar to fenvinline.h removal, this kind of optimization is better
implemented by the compiler.  Also newer code avoid setting exceptions
directly (for instance the code to make new logf, log2f and powf
implementatation to now support SVID compat).

The BZ#94194 [1] the corresponding GCC bug for adding replacements
for these on x86.

Checked on x86_64-linux-gnu and i686-linux-gnu.

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