re PR target/85328 (accessing ymm16 with non-avx512 instruction form)

re PR target/85328 (accessing ymm16 with non-avx512 instruction form)

	PR target/85328
	* config/i386/sse.md
	(<mask_codefor>avx512dq_vextract<shuffletype>64x2_1<mask_name> split,
	<mask_codefor>avx512f_vextract<shuffletype>32x4_1<mask_name> split,
	vec_extract_lo_<mode><mask_name> split, vec_extract_lo_v32hi,
	vec_extract_lo_v64qi): For non-AVX512VL if input is xmm16+ reg
	and output is a reg, avoid creating invalid lowpart subreg, but
	instead split into a 512-bit move.  Don't split if not AVX512VL,
	input is xmm16+ reg and output is a mem.
	(vec_extract_lo_<mode><mask_name>, vec_extract_lo_v32hi,
	vec_extract_lo_v64qi): Don't require split if not AVX512VL, input is
	xmm16+ reg and output is a mem.

	* gcc.target/i386/pr85328.c: New test.

From-SVN: r259344