checks.adb (Install_Null_Excluding_Check): Do not generate checks for an attribute reference that returns an access type.

2005-06-14  Ed Schonberg  <schonberg@adacore.com>

	* checks.adb (Install_Null_Excluding_Check): Do not generate checks
	for an attribute reference that returns an access type.
	(Apply_Discriminant_Check): No need for check if (designated) type has
	constrained partial view.
	(Apply_Float_Conversion_Check): Generate a short-circuit expression for
	both bound checks, rather than a conjunction.
	(Insert_Valid_Check): If the expression is an actual that is an indexed
	component of a bit-packed array, force expansion of the packed element
	reference, because it is specifically inhibited elsewhere.

From-SVN: r101027