re PR target/80286 (AVX2 _mm_cvtsi128_si32 doesn't return a proper 32bits int)

re PR target/80286 (AVX2 _mm_cvtsi128_si32 doesn't return a proper 32bits int)

	PR target/80286
	* config/i386/i386.c (ix86_expand_args_builtin): If op has scalar
	int mode, convert_modes it to mode as unsigned, otherwise use
	lowpart_subreg to mode rather than SImode.
	* config/i386/sse.md (<mask_codefor>ashr<mode>3<mask_name>,
	ashr<mode>3, ashr<mode>3<mask_name>, <shift_insn><mode>3<mask_name>):
	Use DImode instead of SImode for the shift count operand.
	* config/i386/mmx.md (mmx_ashr<mode>3, mmx_<shift_insn><mode>3):
	Likewise.
testsuite/
	* gcc.target/i386/avx-pr80286.c: New test.
	* gcc.dg/pr80286.c: New test.

From-SVN: r246676