powerpc: Refactor powerpc64 lround/lroundf/llround/llroundf

powerpc: Refactor powerpc64 lround/lroundf/llround/llroundf

This patches consolidates all the powerpc {l}lround{f} implementations
on the generic sysdeps/powerpc/fpu/s_{l}lround{f}.c.

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_llround-power8, s_llround-power6x,
	s_llround-power5+, s_llround-ppc64, and s_llroundf-ppc64.
	(CFLAGS-s_llround-power8.c, CFLAGS-s_llround-power6x.c,
	CFLAGS-s_llround-power5+.c): New rule.
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_llround-power5+.c:
	New file.
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_llround-power6x.c:
	Likewise.
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_llround-power8.c:
	Likewise.
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_llround-ppc64.c:
	Likewise.
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_llroundf-ppc64.c:
	Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_llround.c: Move to ...
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_llround.c: ... here.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_llroundf.c: Move to ...
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_llroundf.c: ... here.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_lround.c: Move to ...
	* sysdeps/powerpc/powerpc64/be/fpu/multiarch/s_lround.c: ... here.
	* sysdeps/powerpc/powerpc64/fpu/Makefile
	[$(subdir) == math] (CFLAGS-s_llround.c): New rule.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/Makefile
	(libm-sysdep_routines): Remove s_llround-* objects.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_llround-power5+.S: Remove
	file.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_llround-power6x.S:
	Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_llround-power8.S:
	Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_llround-ppc64.S:
	Likewise.
	* sysdeps/powerpc/powerpc64/fpu/multiarch/s_llroundf-ppc64.S:
	Likewise.
	* sysdeps/powerpc/powerpc64/fpu/s_llround.S: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/s_llroundf.S: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/s_lround.S: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/s_lroundf.S: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/s_llround.c: New file.
	* sysdeps/powerpc/powerpc64/fpu/s_llroundf.c: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/s_lround.c: Likewise.
	* sysdeps/powerpc/powerpc64/fpu/s_lroundf.c: Likewise.
	* sysdeps/powerpc/powerpc64/power5+/fpu/s_llround.S: Likewise.
	* sysdeps/powerpc/powerpc64/power5+/fpu/s_llroundf.S: Likewise.
	* sysdeps/powerpc/powerpc64/power6x/fpu/s_llround.S: Likewise.
	* sysdeps/powerpc/powerpc64/power6x/fpu/s_llroundf.S: Likewise.
	* sysdeps/powerpc/powerpc64/power8/fpu/s_llround.S: Likewise.
	* sysdeps/powerpc/powerpc64/power8/fpu/s_llroundf.S: Likewise.

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