* config/i386/i386.md (UNSPEC_VSIBADDR): New.
	* config/i386/predicates.md (vsib_address_operand,
	vsib_mem_operator): New predicates.
	* config/i386/i386.c (ix86_print_operand_address): Handle
	UNSPEC_VSIBADDR addresses.
	* config/i386/sse.md (avx2_gathersi<mode>, avx2_gatherdi<mode>,
	avx2_gatherdi<mode>256): Adjust expanders to use MEM with
	UNSPEC_VSIBADDR address.
	(*avx2_gathersi<mode>, *avx2_gatherdi<mode>, *avx2_gatherdi<mode>256):
	Adjust insns to use MEM with UNSPEC_VSIBADDR address.

	* gcc.target/i386/avx2-i32gatherd-1.c: Adjust scan-assembler regex
	to work also with -masm=intel and additionally test the xmm vs. ymm
	register type combination on mask/dest and in vsib.
	* gcc.target/i386/avx2-i32gatherd256-1.c: Likewise.
	* gcc.target/i386/avx2-i32gatherd256-3.c: Likewise.
	* gcc.target/i386/avx2-i32gatherd-3.c: Likewise.
	* gcc.target/i386/avx2-i32gatherpd-1.c: Likewise.
	* gcc.target/i386/avx2-i32gatherpd256-1.c: Likewise.
	* gcc.target/i386/avx2-i32gatherpd256-3.c: Likewise.
	* gcc.target/i386/avx2-i32gatherpd-3.c: Likewise.
	* gcc.target/i386/avx2-i32gatherps-1.c: Likewise.
	* gcc.target/i386/avx2-i32gatherps256-1.c: Likewise.
	* gcc.target/i386/avx2-i32gatherps256-3.c: Likewise.
	* gcc.target/i386/avx2-i32gatherps-3.c: Likewise.
	* gcc.target/i386/avx2-i32gatherq-1.c: Likewise.
	* gcc.target/i386/avx2-i32gatherq256-1.c: Likewise.
	* gcc.target/i386/avx2-i32gatherq256-3.c: Likewise.
	* gcc.target/i386/avx2-i32gatherq-3.c: Likewise.
	* gcc.target/i386/avx2-i64gatherd-1.c: Likewise.
	* gcc.target/i386/avx2-i64gatherd256-1.c: Likewise.
	* gcc.target/i386/avx2-i64gatherd256-3.c: Likewise.
	* gcc.target/i386/avx2-i64gatherd-3.c: Likewise.
	* gcc.target/i386/avx2-i64gatherpd-1.c: Likewise.
	* gcc.target/i386/avx2-i64gatherpd256-1.c: Likewise.
	* gcc.target/i386/avx2-i64gatherpd256-3.c: Likewise.
	* gcc.target/i386/avx2-i64gatherpd-3.c: Likewise.
	* gcc.target/i386/avx2-i64gatherps-1.c: Likewise.
	* gcc.target/i386/avx2-i64gatherps256-1.c: Likewise.
	* gcc.target/i386/avx2-i64gatherps256-3.c: Likewise.
	* gcc.target/i386/avx2-i64gatherps-3.c: Likewise.
	* gcc.target/i386/avx2-i64gatherq-1.c: Likewise.
	* gcc.target/i386/avx2-i64gatherq256-1.c: Likewise.
	* gcc.target/i386/avx2-i64gatherq256-3.c: Likewise.
	* gcc.target/i386/avx2-i64gatherq-3.c: Likewise.

From-SVN: r180520