fold-const.c (tree_swap_operands_p): New function to determine the prefered ordering...

fold-const.c (tree_swap_operands_p): New function to determine the prefered ordering of operands.

	* fold-const.c (tree_swap_operands_p): New function to determine
	the prefered ordering of operands.
	(fold): Numerous clean-ups.  Use tree_swap_operands_p when swapping
	operands to commutative, comparison or ternary operators.  Replace
	uses of TREE_SET_CODE with recursive call to fold.  Remove duplicate
	transformation of A ? B : C into !A ? C : B.

From-SVN: r71438