i386: Zhaoxin shijidadao enablement

i386: Zhaoxin shijidadao enablement

This patch enables -march/-mtune=shijidadao, costs and tunings are set
according to the characteristics of the processor.

gcc/ChangeLog:

	* common/config/i386/cpuinfo.h (get_zhaoxin_cpu): Recognize shijidadao.
	* common/config/i386/i386-common.cc: Add shijidadao.
	* common/config/i386/i386-cpuinfo.h (enum processor_subtypes):
	Add ZHAOXIN_FAM7H_SHIJIDADAO.
	* config.gcc: Add shijidadao.
	* config/i386/driver-i386.cc (host_detect_local_cpu):
	Let -march=native recognize shijidadao processors.
	* config/i386/i386-c.cc (ix86_target_macros_internal): Add shijidadao.
	* config/i386/i386-options.cc (m_ZHAOXIN): Add m_SHIJIDADAO.
	(m_SHIJIDADAO): New definition.
	* config/i386/i386.h (enum processor_type): Add PROCESSOR_SHIJIDADAO.
	* config/i386/x86-tune-costs.h (struct processor_costs):
	Add shijidadao_cost.
	* config/i386/x86-tune-sched.cc (ix86_issue_rate): Add shijidadao.
	(ix86_adjust_cost): Ditto.
	* config/i386/x86-tune.def (X86_TUNE_USE_GATHER_2PARTS): Add m_SHIJIDADAO.
	(X86_TUNE_USE_GATHER_4PARTS): Ditto.
	(X86_TUNE_USE_GATHER_8PARTS): Ditto.
	(X86_TUNE_AVOID_128FMA_CHAINS): Ditto.
	* doc/extend.texi: Add details about shijidadao.
	* doc/invoke.texi: Ditto.

gcc/testsuite/ChangeLog:

	* g++.target/i386/mv32.C: Handle new -march
	* gcc.target/i386/funcspec-56.inc: Ditto.