ada: Add minimal support for address clause/aspect on controlled objects

ada: Add minimal support for address clause/aspect on controlled objects

The clause and aspect have been accepted by the compiler for a few years,
but the result is generally an internal compiler error or an incorrect
finalization at run time.

gcc/ada/ChangeLog:

	* exp_ch3.adb (Expand_N_Object_Declaration): Do not insert the tag
	assignment there if the object has the Address aspect.
	* exp_ch7.adb: Add clauses for Aspect package.
	(Build_Finalizer.Process_Object_Declaration): Deal with an object
	with delayed freezing.
	(Insert_Actions_In_Scope_Around): If the target is the declaration
	of an object with address clause or aspect, move all the statements
	that have been inserted after it into the Initialization_Statements
	list of the object.
	* freeze.adb (Check_Address_Clause): Do not reassign the tag here,
	instead set the appropriate flag on the assignment statement.