* exp_dbug.ads (Packed Array Encoding): Document the new encoding for
	the unconstrained case.
	* gcc-interfaces/decl.c (gnat_to_gnu_entity) <E_Array_Type>: Implement
	the encoding.  Do not give a name to the pointer type to the XUT type.
	* gcc-interfaces/utils.c (gnat_pushdecl): Propagate DECL_ORIGINAL_TYPE
	for fat pointer types, if any.  Make sure DECL_ARTIFICIAL is cleared
	on nodes with DECL_ORIGINAL_TYPE set.
	(update_pointer_to): Set DECL_ORIGINAL_TYPE to the original pointer
	for fat pointer types.  Make sure DECL_ARTIFICIAL is cleared.

From-SVN: r151697