sem_util.ads, [...] (Enter_Name): Exclude -gnatwh warning messages for entities in packages which are not used.

2006-10-31  Robert Dewar  <dewar@adacore.com>
	    Hristian Kirtchev  <kirtchev@adacore.com>
	    Ed Schonberg  <schonberg@adacore.com>
        
        * sem_util.ads, sem_util.adb (Enter_Name): Exclude -gnatwh warning
	messages for entities in packages which are not used.
	(Collect_Synchronized_Interfaces): New procedure.
	(Overrides_Synchronized_Primitive): New function.
	(Denotes_Discriminant): Extend predicate to apply to task types.
	Add missing continuation marks in error msgs
	(Unqualify): New function for removing zero or more levels of
	qualification from an expression. There are numerous places where this
	ought to be used, but we currently only deal properly with zero or one
	level.
	(In_Instance); The analysis of the actuals in the instantiation of a
	child unit is not within an instantiation, even though the parent
	instance is on the scope stack.
	(Safe_To_Capture_Value): Exclude the case of variables that are
	renamings.
	(Check_Obsolescent): Removed
	(Is_Aliased_View): A reference to an enclosing instance in an aggregate
	is an aliased view, even when rewritten as a reference to the target
	object in an assignment.
	(Get_Subprogram_Entity): New function
	(Known_To_Be_Assigned): New function
	(Type_Access_Level): Compute properly the access level of a return
	subtype that is an anonymous access type.
	(Explain_Limited_Type): Correct use of "\" for continuation messages.
	(Is_Transfer): The new extended_return_statement causes a transfer of
	control.
	(Has_Preelaborable_Initialization): New function
	(Has_Null_Exclusion): New function. Given a node N, determine whether it
	has a null exclusion depending on its Nkind.
	Change Is_Lvalue to May_Be_Lvalue
	(May_Be_Lvalue): Extensive additional code to deal with subprogram
	arguments (IN parameters are not Lvalues, IN OUT parameters are).
	(Safe_To_Capture_Value): Extend functionality so it can be used for
	the current value condition case.
	(Has_Compatible_Alignment): New function
	(Is_Dependent_Component_Of_Mutable_Object): Revise the tests for mutable
	objects to handle the Ada 2005 case, where aliasedness no longer implies
	that the object is constrained. In particular, for dereferenced names,
	the designated object must be assumed to be unconstrained.
	(Kill_Current_Values): Properly deal with the case where we encounter
	a loop in the scope chain.
	(Safe_To_Capture_Value): Do not let a loop stop us from capturing
	a value.
	(Compile_Time_Constraint_Error): Improve error message in error case

	* exp_ch13.adb (Expand_N_Freeze_Entity): Remove the freezing node
	associated with entities of abstract interface primitives.
	Call Apply_Address_Clause_Check instead of Apply_Alignment_Check

From-SVN: r118312