AVX-512. 75/n. Update vec_init.

AVX-512. 75/n. Update vec_init.

gcc/
	* config/i386/i386.c (ix86_expand_vector_init_duplicate): Handle V64QI
	and V32HI modes, update V8HI, V16QI, V32QI modes handling.
	(ix86_expand_vector_init_general): Handle V64QI and V32HI modes.
	* config/i386/sse.md (define_mode_iterator VI48F_512): Rename to ...
	(define_mode_iterator VF48_I1248): ... this. Extend to AVX-512 modes.
	(define_expand "vec_init<mode>"): Use VF48_I1248.

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: r216401