2007-04-20  Javier Miranda  <miranda@adacore.com>
	    Ed Schonberg  <schonberg@adacore.com>
	    Bob Duff  <duff@adacore.com>
	    Hristian Kirtchev  <kirtchev@adacore.com>

	* exp_aggr.ads, exp_aggr.adb: 
	(Build_Record_Aggr_Code): Add missing initialization of secondary tags
	in extension aggregates.
	(Flatten): Other conditions being met, an aggregate is static if the
	low bound given by component associations is different from the low
	bound of the base index type.
	(Packed_Array_Aggregate_Handled): If the component type is itself a
	packed array or record, the front-end must expand into assignments.
	(Gen_Ctrl_Actions_For_Aggr): In call to Init_Controller, pass False to
	Init_Pr, instead of Ancestor_Is_Expression.
	(Gen_Ctrl_Actions_For_Aggr): When processing an aggregate of a
	coextension chain root, either generate a list controller or use the
	already existing one.
	(Static_Array_Aggregate): New procedure to construct a positional
	aggregate that can be handled by the backend, when all bounds and
	components are compile-time known constants.
	(Expand_Record_Aggregate): Force conversion of aggregates of tagged
	types covering interface types into assignments.
	(Replace_Type): move to Build_Record_Aggr_Code.
	(Expand_Record_Aggr_Code): if the target of the aggregate is an
	interface type, convert to the definite type of the aggregate itself,
	so that needed components are visible.
	(Convert_Aggr_In_Object_Decl): If the aggregate has controlled
	components and the context is an extended return statement do not
	create a transient block for it, to prevent premature finalization
	before the return is executed.
	(Gen_Assign): Do not generate a call to deep adjust routine if the
	component type is itself an array of controlled (sub)-components
	initialized with an inner aggregate.
	(Component_Check): New name for Static_Check. This name is now more
	appropriate, and documentation is added which was missing.
	(Component_Check): Add test for bit aligned component value
	(Component_Not_OK_For_Backend): Renames Has_Delayed_Nested_Aggregate_Or_
	Tagged_Comps, name is more appropriate given added function below.
	(Component_Not_OK_For_Backend): Check for bit aligned component ref.

From-SVN: r125392