ada: Another couple of cleanups in the finalization machinery

ada: Another couple of cleanups in the finalization machinery

For package specs and bodies that need finalizers, Build_Finalizer is
invoked from the Standard scope so it needs to adjust the scope stack
before creating new objects; this changes it to do so only once.

For other kinds of scopes, it is invoked from Expand_Cleanup_Actions,
which assumes that the correct scope is already on the stack; that's
why Cleanup_Scopes adjusts the scope stack explicitly, but it should
use Pop_Scope instead of End_Scope to do it.

gcc/ada/

	* exp_ch7.adb (Build_Finalizer): For package specs and bodies, push
	and pop the specs onto the scope stack only once.
	* inline.adb (Cleanup_Scopes): Call Pop_Scope instead of End_Scope.