re PR target/54700 (Optimize away x<0 as mask argument of a blend.)

re PR target/54700 (Optimize away x<0 as mask argument of a blend.)

	PR target/54700
	* config/i386/sse.md (ssebytemode): Add V16SI, V8SI and V4SI entries.
	(ssefltmodesuffix, ssefltvecmode): New define_mode_attrs.
	(*<sse4_1>_blendv<ssemodesuffix><avxsizesuffix>_lt,
	*<sse4_1>_blendv<ssefltmodesuffix><avxsizesuffix>_ltint,
	*<sse4_1_avx2>_pblendvb_lt): New define_insns.

	* g++.target/i386/sse4_1-pr54700-1.C: New test.
	* g++.target/i386/sse4_1-pr54700-2.C: New test.
	* g++.target/i386/avx-pr54700-1.C: New test.
	* g++.target/i386/avx-pr54700-2.C: New test.
	* g++.target/i386/avx2-pr54700-1.C: New test.
	* g++.target/i386/avx2-pr54700-2.C: New test.
	* g++.target/i386/sse4_1-check.h: New file.
	* g++.target/i386/avx-check.h: New file.
	* g++.target/i386/avx2-check.h: New file.
	* g++.target/i386/m128-check.h: New file.
	* g++.target/i386/m256-check.h: New file.
	* g++.target/i386/avx-os-support.h: New file.

From-SVN: r266621