exp_attr.adb (Enclosing_Object): New function local to handling of access attributes...

exp_attr.adb (Enclosing_Object): New function local to handling of access attributes...

2008-07-31  Gary Dismukes  <dismukes@adacore.com>

	* exp_attr.adb (Enclosing_Object): New function local to handling of
	access attributes,
	for retrieving the innermost enclosing object prefix of a compound name.
	(Expand_N_Attribute_Reference, N_Attribute_Access): In the case where an
	Access attribute has a prefix that is a dereference of an access
	parameter (or the prefix is a subcomponent selected from such a
	dereference), apply an accessibility check to the access parameter.
	Replaces code that rewrote the prefix as a type conversion (and that
	didn't handle subcomponent cases).
	Also, this is now only applied in the case of 'Access.

	* exp_ch6.adb (Expand_Call): Add handling for the case of an access
	discriminant passed as an actual to an access formal, passing the
	Object_Access_Level of the object containing the access discriminant.

From-SVN: r138388