AVX-512. Introduce SKylake server CPU.

AVX-512. Introduce SKylake server CPU.

gcc/
	* config.gcc: Support "skylake-avx512".
        * config/i386/i386-c.c (ix86_target_macros_internal): Handle
        PROCESSOR_SKYLAKE_AVX512.
        * config/i386/i386.c (m_SKYLAKE_AVX512): Define.
        (processor_target_table): Add "skylake-avx512".
        (PTA_SKYLAKE_AVX512): Define.
	(ix86_option_override_internal): Add "skylake_avx512".
        (fold_builtin_cpu): Handle "skylake_avx512", add F_AVX512VL
	F_AVX512BW, F_AVX512DQ, F_AVX512ER, F_AVX512PF, F_AVX512CD.
        * config/i386/i386.h (TARGET_SKYLAKE_AVX512): Define.
        (processor_type): Add PROCESSOR_SKYLAKE_AVX512.
	* doc/invoke.texi (skylake-avx512): New.

libgcc/
	* libgcc/config/i386/cpuinfo.c (enum processor_features): Add
	FEATURE_AVX512VL, FEATURE_AVX512BW, FEATURE_AVX512DQ,
	FEATURE_AVX512CD, FEATURE_AVX512ER, FEATURE_AVX512PF.
	(get_available_features): Habdle new features.

gcc/testsuite/
        * gcc.target/i386/funcspec-5.c: Test avx512vl, avx512bw,
	avx512dq, avx512cd, avx512er, avx512pf and skylake-avx512.
	* gcc.target/i386/builtin_target.c: Test  avx512vl, avx512bw,
	avx512dq, avx512cd, avx512er and avx512pf.

From-SVN: r228009