Optimize vec_extract for 256/512-bit vector when index exceeds the lower 128 bits.

Optimize vec_extract for 256/512-bit vector when index exceeds the lower 128 bits.

-	vextracti32x8	$0x1, %zmm0, %ymm0
-	vmovd	%xmm0, %eax
+	valignd	$8, %zmm0, %zmm0, %zmm1
+	vmovd	%xmm1, %eax

-	vextracti32x8	$0x1, %zmm0, %ymm0
-	vextracti128	$0x1, %ymm0, %xmm0
-	vpextrd	$3, %xmm0, %eax
+	valignd	$15, %zmm0, %zmm0, %zmm1
+	vmovd	%xmm1, %eax

-	vextractf64x2	$0x1, %ymm0, %xmm0
+	valignq	$2, %ymm0, %ymm0, %ymm0

-	vextractf64x4	$0x1, %zmm0, %ymm0
-	vextractf64x2	$0x1, %ymm0, %xmm0
-	vunpckhpd	%xmm0, %xmm0, %xmm0
+	valignq	$7, %zmm0, %zmm0, %zmm0

gcc/ChangeLog:

	PR target/91103
	* config/i386/sse.md (*vec_extract<mode><ssescalarmodelower>_valign):
	New define_insn.

gcc/testsuite/ChangeLog:

	PR target/91103
	* gcc.target/i386/pr91103-1.c: New test.
	* gcc.target/i386/pr91103-2.c: New test.