c4x.md (*db): Enable pattern if TARGET_LOOP_UNSIGNED is non-zero.

	* config/c4x/c4x.md (*db): Enable pattern if TARGET_LOOP_UNSIGNED
	is non-zero.
	(movstrqi_small, movstrqi_large, *cmpstrqi): Add + modifier to address
 	register constraints.
	(*movhi_clobber+1): Modify splitter pattern to handle destination
	register that is used in the source address.
	(*xorhi3_clobber): Replace AND with XOR in call to legitimize_operands.

From-SVN: r26108