mmx.md (*vec_extractv2sf_0): Use gen_lowpart.

mmx.md (*vec_extractv2sf_0): Use gen_lowpart.

	* config/i386/mmx.md (*vec_extractv2sf_0): Use gen_lowpart.
	(*vec_extractv2si_0): Ditto.
	* config/i386/sse.md (*vec_extractv4sf_0): Ditto.
	(zero_extended_scalar_load_operand splitters): Ditto.
	(vec_extract splitters): Ditto.
	(*vec_extractv4si_0_zext): Ditto.
	(avx_<castmode><avxsizesuffix>_<castmode>): Use gen_lowpart
	and lowpart_subreg.
	(avx512f_<castmode><avxsizesuffix>_<castmode>): Ditto.
	(avx512f_<castmode><avxsizesuffix>_256<castmode>): Ditto.
	(*sse4_1_extractps): Use lowpart_subreg.

From-SVN: r235164