* hwint.h (HOST_WIDE_INT_0): New define.
	(HOST_WIDE_INT_0U): Ditto.
	* double-int.c: Use HOST_WIDE_INT_0 instead of (HOST_WIDE_INT) 0.
	* dse.c: Use HOST_WIDE_INT_0U instead of (unsigned HOST_WIDE_INT) 0.
	* simplify-rtx.c: Ditto.
	* tree-object-size.c: Ditto.

From-SVN: r238545