i386.md (define_attr "isa"): Add avx512dq, noavx512dq.

i386.md (define_attr "isa"): Add avx512dq, noavx512dq.

gcc/
	* config/i386/i386.md
	(define_attr "isa"): Add avx512dq, noavx512dq.
	(define_attr "enabled"): Ditto.
	* config/i386/sse.md
	(define_insn "vec_extract_hi_<mode><mask_name>"): Support masking.

Co-Authored-By: Andrey Turetskiy <andrey.turetskiy@intel.com>
Co-Authored-By: Anna Tikhonova <anna.tikhonova@intel.com>
Co-Authored-By: Ilya Tocar <ilya.tocar@intel.com>
Co-Authored-By: Ilya Verbin <ilya.verbin@intel.com>
Co-Authored-By: Kirill Yukhin <kirill.yukhin@intel.com>
Co-Authored-By: Maxim Kuznetsov <maxim.kuznetsov@intel.com>
Co-Authored-By: Michael Zolotukhin <michael.v.zolotukhin@intel.com>
From-SVN: r214088