Don't fold __builtin_ia32_blendvpd w/o sse4.2.

Don't fold __builtin_ia32_blendvpd w/o sse4.2.

__builtin_ia32_blendvpd is defined under sse4.1 and gimple folded
to ((v2di) c) < 0 ? b : a where vec_cmpv2di is under sse4.2 w/o which
it's veclowered to scalar operations and not combined back in rtl.

gcc/ChangeLog:

	PR target/104946
	* config/i386/i386-builtin.def (BDESC): Add
	CODE_FOR_sse4_1_blendvpd for IX86_BUILTIN_BLENDVPD.
	* config/i386/i386.cc (ix86_gimple_fold_builtin): Don't fold
	__builtin_ia32_blendvpd w/o sse4.2

gcc/testsuite/ChangeLog:

	* gcc.target/i386/sse4_1-blendvpd-1.c: New test.