re PR rtl-optimization/55740 (ICE in verify_loop_structure, at cfgloop.c:1582, error: loop 2's header does not belong directly to it)

2012-12-20  Richard Biener  <rguenther@suse.de>

	PR middle-end/55740
	* cfghooks.c (merge_blocks): Properly handle merging of
	two loop headers.

	* g++.dg/torture/pr55740.C: New testcase.

From-SVN: r194633