fold-const.c (fold_binary): Fold (X & Y) ^ Y as the equivalent ~X & Y, and the symmetry related transformations.


	* fold-const.c (fold_binary) <BIT_XOR_EXPR>: Fold (X & Y) ^ Y as
	the equivalent ~X & Y, and the symmetry related transformations.
	(fold_binary) <BIT_AND_EXPR>: Similarly, fold (X ^ Y) & Y as 
	~X & Y, and symmetry related transforms.

	* gcc.dg/fold-andxor-1.c: New test case.
	* gcc.dg/fold-xorand-1.c: Likewise.

From-SVN: r112459