Enable GCC support for SERIALIZE

Enable GCC support for SERIALIZE

2020-03-04  Hongtao Liu  <hongtao.liu@intel.com>
2020-03-04  Wei Xiao  <wei3.xiao@intel.com>

gcc/Changelog:
	* gcc/common/config/i386/i386-common.c (OPTION_MASK_ISA2_SERIALIZE_SET,
	OPTION_MASK_ISA2_SERIALIZE_UNSET): New macros.
	(ix86_handle_option): Handle -mserialize.
	* gcc/config.gcc (serializeintrin.h): New header file.
	* gcc/config/i386/cpuid.h (bit_SERIALIZE): New bit.
	* gcc/config/i386/driver-i386.c (host_detect_local_cpu): Detect
	-mserialize.
	* gcc/config/i386/i386-builtin.def: Add new builtin.
	* gcc/config/i386/i386-c.c (__SERIALIZE__): New macro.
	* gcc/config/i386/i386-options.c (ix86_target_opts_isa2_opts):
	  Add -mserialize.
	* (ix86_valid_target_attribute_inner_p): Add target attribute
	* for serialize.
	* gcc/config/i386/i386.h (TARGET_SERIALIZE, TARGET_SERIALIZE_P):
	  New macros.
	* gcc/config/i386/i386.md (UNSPECV_SERIALIZE): New unspec.
	  (serialize): New define_insn.
	* gcc/config/i386/i386.opt (mserialize): New option
	* gcc/config/i386/immintrin.h: Include serailizeintrin.h.
	* gcc/config/i386/serializeintrin.h: New header file.
	* gcc/doc/invoke.texi: Add documents for -mserialize.

gcc/testsuite/Changelog
	* gcc/testsuite/gcc.target/i386/serialize-1.c: New test.
	* gcc/testsuite/g++.dg/other/i386-2.C: Add -mserialize.
	* gcc/testsuite/g++.dg/other/i386-3.C: Ditto.
	* gcc/testsuite/gcc.target/i386/funcspec-56.inc: Ditto.
	* gcc/testsuite/gcc.target/i386/sse-12.c: Ditto.
	* gcc/testsuite/gcc.target/i386/sse-13.c: Ditto.
	* gcc/testsuite/gcc.target/i386/sse-14.c: Ditto.
	* gcc/testsuite/gcc.target/i386/sse-22.c: Ditto.
	* gcc/testsuite/gcc.target/i386/sse-23.c: Ditto.