Simple bitop reassoc in match.pd

Simple bitop reassoc in match.pd

2016-05-10  Marc Glisse  <marc.glisse@inria.fr>

gcc/
	* fold-const.c (fold_binary_loc) [(X ^ Y) & Y]: Remove and merge with...
	* match.pd ((X & Y) ^ Y): ... this.
	((X & Y) & Y, (X | Y) | Y, (X ^ Y) ^ Y, (X & Y) & (X & Z), (X | Y)
	| (X | Z), (X ^ Y) ^ (X ^ Z)): New transformations.

gcc/testsuite/
	* gcc.dg/tree-ssa/bit-assoc.c: New testcase.
	* gcc.dg/tree-ssa/pr69270.c: Adjust.
	* gcc.dg/tree-ssa/vrp59.c: Disable forwprop.

From-SVN: r236103