Fix various memory leaks

Fix various memory leaks

	* gimple-ssa-strength-reduction.c (create_phi_basis):
	Use auto_vec.
	* passes.c (release_dump_file_name): New function.
	(pass_init_dump_file): Used from this function.
	(pass_fini_dump_file): Likewise.
	* tree-sra.c (convert_callers_for_node): Use xstrdup_for_dump.
	* var-tracking.c (vt_initialize): Use pool_allocator.

From-SVN: r230152