re PR middle-end/56461 (GCC is leaking lots of memory)

re PR middle-end/56461 (GCC is leaking lots of memory)

	PR middle-end/56461
	* tree-vectorizer.h (vect_get_slp_defs): Change 3rd argument
	type to vec<vec<tree> > *.
	* tree-vect-slp.c (vect_get_slp_defs): Likewise.  Change vec_defs
	to be vec<tree> instead of vec<tree> *, set vec_defs
	to vNULL and call vec_defs.create (number_of_vects), adjust other
	uses of vec_defs.
	* tree-vect-stmts.c (vect_get_vec_defs, vectorizable_call,
	vectorizable_condition): Adjust vect_get_slp_defs callers.

From-SVN: r196360