Change use to type-based pool allocator in df-scan.c.

Change use to type-based pool allocator in df-scan.c.

	* df-scan.c (struct df_scan_problem_data):Use new type-based pool allocator.
	(df_scan_free_internal) Likewise.
	(df_scan_alloc) Likewise.
	(df_grow_reg_info) Likewise.
	(df_free_ref) Likewise.
	(df_insn_create_insn_record) Likewise.
	(df_mw_hardreg_chain_delete) Likewise.
	(df_insn_info_delete) Likewise.
	(df_free_collection_rec) Likewise.
	(df_mw_hardreg_chain_delete_eq_uses) Likewise.
	(df_sort_and_compress_mws) Likewise.
	(df_ref_create_structure) Likewise.
	(df_ref_record) Likewise.

From-SVN: r223954