itypes.ads, itypes.adb (Create_Null_Excluding_Itype): New subprogram that given an entity T creates and returns an Itype that...

2005-09-01  Javier Miranda  <miranda@adacore.com>

	* itypes.ads, itypes.adb (Create_Null_Excluding_Itype): New subprogram
	that given an entity T creates and returns an Itype that duplicates the
	contents of T. The returned Itype has the null-exclusion
	attribute set to True, and its Etype attribute references T
	to keep the association between the two entities.
	Update copyright notice

	* sem_aggr.adb (Check_Can_Never_Be_Null,
	Aggregate_Constraint_Checks, Resolve_Aggregate,
	Resolve_Array_Aggregate, Resolve_Record_Aggregate): Code cleanup.

	* sem_ch5.adb (Analyze_Assignment): Code cleanup.

From-SVN: r103868