fpe-trapping: Simplify. * lib/fpe-trapping.h (sigfpe_on_invalid): Remove all platform specific code. Just rely on feclearexcept and feenableexcept. * m4/fpe-trapping.m4: Renamed from m4/fpe.m4. (gl_FPE_TRAPPING): Greatly simplify. * modules/fpe-trapping (Files): Use m4/fpe-trapping.m4 instead of m4/fpe.m4. Remove m4/mathfunc.m4, m4/musl.m4. (Depends-on): Add fenv-exceptions-trapping. * tests/test-fenv-except-state-2.c (main): Update skip message. * tests/test-fenv-except-tracking-2.c (main): Likewise. * tests/test-fenv-except-tracking-3.c (main): Likewise. * tests/test-fenv-except-tracking-5.c (main): Likewise. * tests/test-nan-2.c (main): Likewise. * tests/test-snan-2.c (main): Likewise.