tree-ssa-reassoc.c (maybe_optimize_range_tests): Return boolean indicating if a gimple conditional was optimized to true/false.

	* tree-ssa-reassoc.c (maybe_optimize_range_tests): Return boolean
	indicating if a gimple conditional was optimized to true/false.
	(reassociate_bb): Bubble up return value from
	maybe_optimize_range_tests.
	(do_reassoc): Similarly, but for reassociate_bb.
	(execute_reassoc): Return TODO_cleanup_cfg as needed.

	* gcc.dg/tree-ssa/reassoc-43.c: New test.

From-SVN: r231277