re PR middle-end/62263 (Good codegen for bitwise rotate requires code that is technically undefined behavior)

	PR middle-end/62263
	PR middle-end/82498
	* tree-ssa-forwprop.c (simplify_rotate): Allow def_arg1[N]
	to be any operand_equal_p operands.  For & (B - 1) require
	B to be power of 2.  Recognize
	(X << (Y & (B - 1))) | (X >> ((-Y) & (B - 1))) and similar patterns.

	* c-c++-common/rotate-5.c (f2): New function.  Move old
	function to ...
	(f4): ... this.  Use 127 instead of 128.
	(f3, f5, f6): New functions.
	(main): Test all f[1-6] functions, with both 0 and 1 as
	second arguments.
	* c-c++-common/rotate-6.c: New test.
	* c-c++-common/rotate-6a.c: New test.
	* c-c++-common/rotate-7.c: New test.
	* c-c++-common/rotate-7a.c: New test.
	* c-c++-common/rotate-8.c: New test.

From-SVN: r253760