* ipa-split.c (verify_non_ssa_vars): Break out from ...; perform DFS walk

	* ipa-split.c (verify_non_ssa_vars): Break out from ...; perform DFS walk
	backwards from entry_bb to check only those basic block of header
	that might lead to execution of split part.
	(consider_split) ... here.
	(find_return_bb): Allow assignment in return BB.
	(find_retval): New.
	(split_function): Fix name of cloned function; take care of updating return
	value in return_bb containing move.

	* gcc.dg/tree-ssa/ipa-split-5.c: New function.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@161744 138bc75d-0d04-0410-961f-82ee72b054a4