tree-vect-stmts.c (vectorizable_shift): If op1 is vect_external_def in a loop and...

tree-vect-stmts.c (vectorizable_shift): If op1 is vect_external_def in a loop and has different type from op0...

	* tree-vect-stmts.c (vectorizable_shift): If op1 is vect_external_def
	in a loop and has different type from op0, cast it to op0's type
	before the loop first.  For slp give up.  Don't crash if op1_vectype
	is NULL.

	* gcc.dg/vshift-3.c: New test.
	* gcc.dg/vshift-4.c: New test.
	* gcc.dg/vshift-5.c: New test.

From-SVN: r180704