re PR target/52607 (v4df __builtin_shuffle with {0,2,1,3} or {1,3,0,2})

re PR target/52607 (v4df __builtin_shuffle with {0,2,1,3} or {1,3,0,2})

	PR target/52607
	* config/i386/i386.md ("isa" attribute): Add avx2 and noavx2.
	("enabled" attribute): Handle avx2 and noavx2 isas.
	* config/i386/sse.md (avx2_vec_dupv8sf_1, avx2_pbroadcast<mode>_1):
	New insns.
	(vec_dup<mode>): Add avx2 =x,x alternative.
	(vec_dup<mode> splitter): Don't split if TARGET_AVX2.
	(*avx_vperm_broadcast_<mode>): Don't split V4DFmode if TARGET_AVX2.
	For TARGET_AVX2, V8SFmode and elt == 0 split into vbroadcastss.
	* config/i386/i386.c (expand_vec_perm_pshufb): Emit also vpermps
	for V8SFmode.
	(expand_vec_perm_1): For broadcasts, use avx2_pbroadcast<mode>_1
	if possible, handle also V8SFmode.

From-SVN: r185577