re PR tree-optimization/59519 (ICE on valid code at -O3 on x86_64-linux-gnu in slpeel_update_phi_nodes_for_guard1, at tree-vect-loop-manip.c:486)

	PR tree-optimization/59519
	* tree-vect-loop-manip.c (slpeel_update_phi_nodes_for_guard1): Don't
	ICE if get_current_def (current_new_name) is already non-NULL, as long
	as it is a phi result of some other phi in *new_exit_bb that has
	the same argument.

	* gcc.dg/vect/pr59519-1.c: New test.
	* gcc.dg/vect/pr59519-2.c: New test.

From-SVN: r206333