fold-const.c (fold_binary_loc): Remove X ^ C1 == C2 -> X == (C1 ^ C2) which is already implemented in match.pd.

2015-07-31  Richard Biener  <rguenther@suse.de>

	* fold-const.c (fold_binary_loc): Remove X ^ C1 == C2
	-> X == (C1 ^ C2) which is already implemented in match.pd.
	Remove redundant dispatching to fold_relational_const.
	Move unordered self and NaN compares ...
	* match.pd: ... as patterns here.  Remove some stray captures
	and add a comment.

From-SVN: r226434