DR 176 permissiveness

	DR 176 permissiveness
gcc/
	* dwarf2out.c (get_context_die): Take TYPE_MAIN_VARIANT.
gcc/cp/
	* class.c (build_self_reference): Call set_underlying_type.
	* decl.c (check_elaborated_type_specifier): Don't complain about
	injected-class-name.
	(type_is_deprecated): Use TYPE_MAIN_VARIANT.
	* pt.c (convert_template_argument): Handle injected-class-name used
	as template template argument.
	* typeck2.c (abstract_virtuals_error): Use TYPE_MAIN_VARIANT.

From-SVN: r154354