This introduces simplify_logical_relational_operation.  Currently the
only thing implemented it can simplify is the IOR of two CONDs of the
same arguments.


	* simplify-rtx.c (comparison_to_mask): New function.
	(mask_to_comparison): New function.
	(simplify_logical_relational_operation): New function.
	(simplify_binary_operation_1): Call
	simplify_logical_relational_operation.

From-SVN: r277931