Fix testcase failure.

Fix testcase failure.

gcc/testsuite/ChangeLog:

	* gcc.target/i386/pieces-memcpy-10.c: Use -mmove-max=256 and
	-mstore-max=256.
	* gcc.target/i386/pieces-memcpy-6.c: Ditto.
	* gcc.target/i386/pieces-memset-38.c: Ditto.
	* gcc.target/i386/pieces-memset-40.c: Ditto.
	* gcc.target/i386/pieces-memset-41.c: Ditto.
	* gcc.target/i386/pieces-memset-42.c: Ditto.
	* gcc.target/i386/pieces-memset-43.c: Ditto.
	* gcc.target/i386/pieces-strcpy-2.c: Ditto.

(cherry picked from commit ea9c508927ec032c6d67a24df59ffa429e4d3d95)