decl.c (gnat_to_gnu_entity): Translate System.Address into ptr_type_node for every foreign convention.

	* gcc-interface/decl.c (gnat_to_gnu_entity) <E_Variable>: Translate
	System.Address into ptr_type_node for every foreign convention.
	(gnat_to_gnu_subprog_type): Likewise for result and parameter types.
	(gnat_to_gnu_param): Do not do it here for GCC builtins.
	(intrin_return_compatible_p): Likewise.

From-SVN: r243340