PR rtl-optimization/29924

	* loop-unroll.c (split_edge_and_insert): Handle the case insns is NULL.
	(unroll_loop_runtime_iterations): Assert that the argument passed to
	split_edge_and_insert is not NULL.
	* loop-doloop.c (add_test): Ditto.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@119078 138bc75d-0d04-0410-961f-82ee72b054a4