Bug 2183081

As mentioned in https://gcc.gnu.org/PR109344, the RHEL 8 (likely older RHEL too, RHEL 9 seems to be fine) glibc /usr/include/bits/fenv.h header contains an incorrect
inline version of feraiseexcept:
      /* One example of an invalid operation is 0.0 / 0.0.  */
      float __f = 0.0;

# ifdef __SSE_MATH__
      __asm__ __volatile__ ("divss %0, %0 " : : "x" (__f));
# else
      __asm__ __volatile__ ("fdiv %%st, %%st(0); fwait"
                            : "=t" (__f) : "0" (__f));
# endif
and
      float __f = 1.0;
      float __g = 0.0;

# ifdef __SSE_MATH__
      __asm__ __volatile__ ("divss %1, %0" : : "x" (__f), "x" (__g));
# else
      __asm__ __volatile__ ("fdivp %%st, %%st(1); fwait"
                            : "=t" (__f) : "0" (__f), "u" (__g) : "st(1)");
# endif
is incorrect for defined(__SSE_MATH__), because it modifies whatever register holds __f without telling the compiler about it.
It should be
      __asm__ __volatile__ ("divss %0, %0 " : "+x" (__f));
and
      __asm__ __volatile__ ("divss %1, %0" : "+x" (__f) : "x" (__g));
Without that, GCC can assume after pxor %xmm0, %xmm0 that %xmm0 contains 0.0
even after divss %xmm0, %xmm0, which is not the case, it is then qNaN, and so doesn't raise division by zero exception when trying to divide 1.0 by that.