re PR target/83203 (Inefficient int to avx2 vector conversion)

re PR target/83203 (Inefficient int to avx2 vector conversion)

	PR target/83203
	* config/i386/i386.c (ix86_expand_vector_init_one_nonzero): If one_var
	is 0, for V{8,16}S[IF] and V[48]D[IF]mode use gen_vec_set<mode>_0.
	* config/i386/sse.md (VI8_AVX_AVX512F, VI4F_256_512): New mode
	iterators.
	(ssescalarmodesuffix): Add 512-bit vectors.  Use "d" or "q" for
	integral modes instead of "ss" and "sd".
	(vec_set<mode>_0): New define_insns for 256-bit and 512-bit
	vectors with 32-bit and 64-bit elements.
	(vecdupssescalarmodesuffix): New mode attribute.
	(vec_dup<mode>): Use it.

From-SVN: r256556