Don't add crtfastmath.o for -shared.

Don't add crtfastmath.o for -shared.

Patches [1] and [2] fixed PR55522 for x86-linux but left all other x86
targets unfixed (x86-cygwin, x86-darwin and x86-mingw32).
This patch applies a similar change to other specs using crtfastmath.o.

[1] https://gcc.gnu.org/pipermail/gcc-patches/2022-December/608528.html
[2] https://gcc.gnu.org/pipermail/gcc-patches/2022-December/608529.html

gcc/ChangeLog:

	PR target/55522
	* config/i386/cygwin.h (ENDFILE_SPEC): Link crtfastmath.o
	whenever -mdaz-ftz is specified. Don't link crtfastmath.o when
	-share or -mno-daz-ftz is specified.
	* config/i386/darwin.h (ENDFILE_SPEC): Ditto.
	* config/i386/mingw32.h (ENDFILE_SPEC): Ditto.