ada: Fix finalization issues in extended return statements

ada: Fix finalization issues in extended return statements

The first issue pertains to return objects of (class-wide) interface types,
which need to be adjusted if the type is not inherently limited.  The second
issue is for return objects of non-class-wide types that are initialized by
a function call, which can use a direct renaming only if the object doing
the capture of the function call is flagged by Is_Related_To_Func_Return.
The third one is that, in the second case, we may need to reassign the tag.

gcc/ada/

	* exp_ch3.adb (Expand_N_Object_Declaration): For a special return
	object of an interface type that is not inherently limited, make
	a call to the Adjust primitive after doing the copy.  For a special
	return object of a non-class-wide type initialized by a function
	call, use a direct renaming only if the object doing the capture
	is flagged by Is_Related_To_Func_Return.  For a special return
	object using a direct renaming, reassign the tag, if need be.
	* exp_ch6.adb (Expand_Simple_Function_Return): Fix comment.
	* exp_util.adb (Is_Related_To_Func_Return): Accept both regular and
	renaming object declarations for return objects.