* sysdeps/powerpc/powerpc32/power6/memset.S: Update comments.
Specify .machine power6 to get ISA-V2.0 branch hints. Unroll loops
and avoid branch misspredicts for > 31 bytes memset case.
* sysdeps/powerpc/powerpc64/power6/memset.S: Likewise.
Remove toc ref to __cache_line_size.
* sysdeps/powerpc/powerpc32/power4/memcmp.S: Specify .machine power4
to get ISA-V2.0 branch hints.
* sysdeps/powerpc/powerpc32/power4/memcpy.S: Likewise
* sysdeps/powerpc/powerpc32/power4/memset.S: Likewise
* sysdeps/powerpc/powerpc32/power6/memcpy.S: Likewise.
* sysdeps/powerpc/powerpc64/power4/memcmp.S: Likewise.
* sysdeps/powerpc/powerpc64/power4/memcpy.S: Likewise.
* sysdeps/powerpc/powerpc64/power4/memset.S: Likewise.
Remove toc ref to __cache_line_size.
* sysdeps/powerpc/powerpc32/power6/fpu/s_llrint.S:
Include math_ldbl_opt.h.