Support clwb x86 instruction.

gcc/
	* common/config/i386/i386-common.c (OPTION_MASK_ISA_CLWB_UNSET,
	OPTION_MASK_ISA_CLWB_SET): New.
	(ix86_handle_option): Handle OPT_mclwb.
	* config.gcc: Add clwbintrin.h.
	* config/i386/clwbintrin.h: New file.
	* config/i386/cpuid.h (bit_CLWB): Define.
	* config/i386/driver-i386.c (host_detect_local_cpu): Detect clwb. 
	* config/i386/i386-c.c (ix86_target_macros_internal): Define
	__CLWB__.
	* config/i386/i386.c (ix86_target_string): Add -mclwb.
	(PTA_CLWB): Define.
	(ix86_option_override_internal): Handle new option.
	(ix86_valid_target_attribute_inner_p): Add clwb.
	(ix86_builtins): Add IX86_BUILTIN_CLWB.
	(ix86_init_mmx_sse_builtins): Add __builtin_ia32_clwb.
	(ix86_expand_builtin): Handle IX86_BUILTIN_CLWB.
	* config/i386/i386.h (TARGET_CLWB, TARGET_CLWB_P): Define.
	* config/i386/i386.md (unspecv): Add UNSPECV_CLWB.
	(clwb): New instruction.
	* config/i386/i386.opt: Add mclwb.
	* config/i386/x86intrin.h: Include clwbintrin.h.

gcc/testsuite/

	* g++.dg/other/i386-2.C: Add -mclwb.
	* g++.dg/other/i386-3.C: Ditto.
	* gcc.target/i386/clwb-1.c: New test.
	* gcc.target/i386/sse-12.c: Add new options.
	* 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.

From-SVN: r217933