2011-08-02  Ed Schonberg  <schonberg@adacore.com>

	* atree.h, atree.ads, atree.adb: New subprograms to manipulate Elist5.
	* par_ch8.adb (P_Use_Type): initialize Used_Operations for node.
	* sinfo.ads, sinfo.adb (Used_Operations): new attribute of
	use_type_clauses, to handle more efficiently use_type and use_all_type
	constructs.
	* sem_ch8.adb: Rewrite Use_One_Type and End_Use_Type to handle the
	Ada2012 Use_All_Type clause.
	(Use_Class_Wide_Operations): new procedure.

From-SVN: r177090