Delete x86 pcommit instruction support, which has been deprecated:

https://software.intel.com/en-us/blogs/2016/09/12/deprecate-pcommit-instruction

gcc/

	* common/config/i386/i386-common.c (OPTION_MASK_ISA_PCOMMIT_UNSET,
	OPTION_MASK_ISA_PCOMMIT_SET): Deleted definitions.
	(ix86_handle_option): Deleted handle of OPT_mpcommit.
	* config.gcc: Deleted pcommitintrin.h
	* config/i386/pcommitintrin.h: Deleted file.
	* config/i386/cpuid.h (bit_PCOMMIT): Deleted.
	* config/i386/driver-i386.c (host_detect_local_cpu): Deleted pcommit
	detection.
	* config/i386/i386-c.c (ix86_target_macros_internal): Deleted define
	__PCOMMIT__.
	* config/i386/i386.c (ix86_target_string): Deleted -mpcommit.
	(PTA_PCOMMIT): Deleted define.
	(ix86_option_override_internal): Deleted handle of option.
	(ix86_valid_target_attribute_inner_p): Deleted pcommit.
	* config/i386/i386-builtin.def (IX86_BUILTIN_PCOMMIT,
	__builtin_ia32_pcommit): Deleted.
	* config/i386/i386.h (TARGET_PCOMMIT, TARGET_PCOMMIT_P): Deleted.
	* config/i386/i386.md (unspecv): Deleted UNSPECV_PCOMMIT.
	(pcommit): Deleted instruction.
	* config/i386/i386.opt: Mention -mpcommit deprecation.
	* config/i386/x86intrin.h: Deleted inclusion of pcommitintrin.h.

gcc/testsuite/

	* gcc.target/i386/pcommit-1.c: Deleted.
	* gcc.target/i386/sse-12.c: Deleted -pcommit option.
	* gcc.target/i386/sse-13.c: Ditto.
	* gcc.target/i386/sse-14.c: Ditto.
	* gcc.target/i386/sse-22.c: Ditto.
	* gcc.target/i386/sse-23.c: Ditto.
	* g++.dg/other/i386-2.C: Ditto.

From-SVN: r240816