* einfo.adb (Write_Field19_Name): Body_Entity is also defined for
	a generic package.

	* einfo.ads: Body_Entity is also defined for generic package.
	Documentation change only

	* exp_aggr.adb (Build_Array_Aggr_Code): When expanding an
	others_choice for a discriminated component initialization,
	convert discriminant references into the corresponding discriminals.

	* exp_ch3.adb (Get_Simple_Init_Val): Add qualification to aggregate
	only if original type is private and expression has to be wrapped
	in a conversion.

	* checks.adb:
	(Apply_Constraint_Check): Do not perform length check
	if expression is an aggregate with only an others_choice.
	(Length_N_Cond): two references to the same in_parameter
	(typically the discriminal in an init_proc) denote the same value.
	Two useful optimization uncovered by bugfixes above.

From-SVN: r46165