ada: Remove couple of irregular calls to Resolve_Aggr_Expr

ada: Remove couple of irregular calls to Resolve_Aggr_Expr

The function is supposed to be passed an expression, but it is passed the
enclosing N_Component_Association node in a couple of cases, only to give
an error that can as well be given in the caller, at the cost of bypasses
to disable most of its processing.

gcc/ada/ChangeLog:

	* sem_aggr.adb (Resolve_Array_Aggregate): In the case of an others
	choice with a box, do not call Resolve_Aggr_Exp and give the error
	for a multidimensional array directly.
	(Resolve_Aggr_Expr): Remove bypasses for above case.