powerpc: refactor powerpc64 lrint/lrintf/llrint/llrintf

powerpc: refactor powerpc64 lrint/lrintf/llrint/llrintf

This patches consolidates all the powerpc llrint{f} implementations on
the generic sysdeps/powerpc/fpu/s_llrint{f}.

The IFUNC support is also moved only to powerpc64 only, since for
powerpc64le generic implementation resulting in optimized code.

Checked on powerpc-linux-gnu (built without --with-cpu, with
--with-cpu=power4 and with --with-cpu=power5+ and --disable-multi-arch),
powerpc64-linux-gnu (built without --with-cp and with --with-cpu=power5+
and --disable-multi-arch).

	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/Makefile
	(libm-sysdep_routines): Add s_llrint-power8, s_llrint-power6x, and
	s_llrint-ppc64.
	(CFLAGS-s_llrint-power8.c, CFLAGS-s_llrint-power6x.c): New rule.
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_llrint-power6x.c: New
	file.
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_llrint-power8.c:
	Likewise.
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_llrint-ppc64.c:
	Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_lrint.c: Move to ...
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_lrint.c: ... here.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_llrint.c: Move to ...
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_llrint.c: ... here.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_llrintf.c: Move to ...
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_llrintf.c: ... here.
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_lrint.c: New file.
	* sysdeps/powerpc/powerpc64/fpu/Makefile: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile
	(libm-sysdep_routines): Remove s_llrint-* objects.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_llrint-power6x.S: Remove
	file.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_llrint-power8.S:
	Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_llrint-ppc64.S: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/s_llrint.c: New file.
	* sysdeps/powerpc/powerpc64/fpu/s_llrintf.c: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/s_lrint.c: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/s_lrintf.c: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/s_llrint.S: Remove file.
	* sysdeps/powerpc/powerpc64/fpu/s_llrintf.S: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/s_lrint.S: Likewise.
	* sysdeps/powerpc/powerpc64/power6x/fpu/s_llrint.S: Likewise.
	* sysdeps/powerpc/powerpc64/power8/fpu/s_llrint.S: Likewise.

Reviewed-by: Gabriel F. T. Gomes <gabrielftg@linux.ibm.com>