tree-vect-stmts.c (scan_operand_equal_p): Look through MEM_REF with SSA_NAME address of POINTER_PLUS_EXPR.

	* tree-vect-stmts.c (scan_operand_equal_p): Look through MEM_REF
	with SSA_NAME address of POINTER_PLUS_EXPR.  Handle MULT_EXPR
	and casts in offset when different, both through gimple stmts
	and through trees.  Rewritten using loops to minimize code duplication
	for each operand.

	* g++.dg/vect/simd-6.cc: Replace xfail with target x86.
	* g++.dg/vect/simd-9.cc: Likewise.

	* testsuite/libgomp.c++/scan-13.C: Replace xfail with target x86.
	* testsuite/libgomp.c++/scan-16.C: Likewise.

From-SVN: r273249