re PR target/70300 (ICE: in extract_constrain_insn, at recog.c:2190 (insn does not...

re PR target/70300 (ICE: in extract_constrain_insn, at recog.c:2190 (insn does not satisfy its constraints) with -mtune=amdfam10 -mavx512bw)

	PR target/70300
	* config/i386/i386.md (cvtsd2ss splitter): Unpack in destination
	instead of source if operands[1] is xmm16 and above and
	!TARGET_AVX512VL.  Use avx512f_vec_dupv16sf_1 instead of
	vec_interleave_lowv4sf if we need to unpack xmm16 and above.

	* gcc.target/i386/pr70300.c: New test.

From-SVN: r234393