sparc: M7 optimized memset/bzero

sparc: M7 optimized memset/bzero

Support added to identify Sparc M7/T7/S7/M8/T8 processor capability.
Performance tests run on Sparc S7 using new code and old niagara4 code.

Optimizations for memset also apply to bzero as they share code.

For memset/bzero, performance comparison with niagara4 code:
For memset nonzero data,
  256-1023 bytes - 60-90% gain (in cache); 5% gain (out of cache)
  1K+ bytes - 80-260% gain (in cache); 40-80% gain (out of cache)
For memset zero data (and bzero),
  256-1023 bytes - 80-120% gain (in cache), 0% gain (out of cache)
  1024+ bytes - 2-4x gain (in cache), 10-35% gain (out of cache)

Tested in sparcv9-*-* and sparc64-*-* targets in both multi and
non-multi arch configurations.

	Patrick McGehearty <patrick.mcgehearty@oracle.com>
	Adhemerval Zanella  <adhemerval.zanella@linaro.org>

	* sysdeps/sparc/sparc32/sparcv9/multiarch/Makefile
	(sysdeps_routines): Add memset-niagara7.
	* sysdeps/sparc/sparc64/multiarch/Makefile (sysdes_rotuines):
	Likewise.
	* sysdeps/sparc/sparc32/sparcv9/multiarch/memset-niagara7.S: New
	file.
	* sysdeps/sparc/sparc64/multiarch/memset-niagara7.S: Likewise.
	* sysdeps/sparc/sparc64/multiarch/ifunc-impl-list.c
	(__libc_ifunc_impl_list): Add __bzero_niagara7 and __memset_niagara7.
	* sysdeps/sparc/sparc64/multiarch/ifunc-memset.h (IFUNC_SELECTOR):
	Add niagara7 option.
	* NEWS: Mention sparc m7 optimized memcpy, mempcpy, memmove, and
	memset.