Enable TARGET_TSXLDTRK for GCC support.

Enable TARGET_TSXLDTRK for GCC support.

gcc/
	* common/config/i386/i386-common.c (OPTION_MASK_ISA2_TSXLDTRK_SET,
	OPTION_MASK_ISA2_TSXLDTRK_UNSET): New macros.
	* config.gcc: Add tsxldtrkintrin.h to extra_headers.
	* config/i386/driver-i386.c (host_detect_local_cpu): Detect
	TSXLDTRK.
	* config/i386/i386-builtin.def: Add new builtins.
	* config/i386/i386-c.c (ix86_target_macros_internal): Define
	__TSXLDTRK__.
	* config/i386/i386-options.c (ix86_target_string): Add
	-mtsxldtrk.
	(ix86_valid_target_attribute_inner_p): Add attribute tsxldtrk.
	* config/i386/i386.h (TARGET_TSXLDTRK, TARGET_TSXLDTRK_P):
	New.
	* config/i386/i386.md (define_c_enum "unspec"): Add
	UNSPECV_SUSLDTRK, UNSPECV_RESLDTRK.
	(TSXLDTRK): New define_int_iterator.
	("<tsxldtrk>"): New define_insn.
	* config/i386/i386.opt: Add -mtsxldtrk.
	* config/i386/immintrin.h: Include tsxldtrkintrin.h.
	* config/i386/tsxldtrkintrin.h: New.
	* doc/invoke.texi: Document -mtsxldtrk.

gcc/testsuite/
	* g++.dg/other/i386-2.c: Add -mtsxldtrk.
	* g++.dg/other/i386-3.c: Likewise.
	* gcc.target/i386/sse-12.c: Likewise.
	* gcc.target/i386/sse-13.c: Likewise.
	* gcc.target/i386/sse-14.c: Likewise.
	* gcc.target/i386/sse-22.c: Likewsie.
	* gcc.target/i386/sse-23.c: Likewise.
	* gcc.target/i386/tsxldtrk-1.c: New test.
	* gcc.target/i386/funcspec-56.inc: Add target attribute tests
	for tsxldtrk.