Make lambda conversion op and op() non-static.

Make lambda conversion op and op() non-static.

	* semantics.c (maybe_add_lambda_conv_op): Make non-static.
	Also add the thunk function returned by the conversion op.
	Mark the conversion deleted if the op() is variadic.
	* decl2.c (mark_used): Give helpful message about deleted conversion.
	* parser.c (cp_parser_lambda_declarator_opt): Don't make op() static.
	* semantics.c (finish_this_expr): Adjust.
	* mangle.c (write_closure_type_name): Adjust.
	* decl.c (grok_op_properties): Don't allow it.
	* call.c (build_user_type_conversion_1): No static conversion ops.
	(build_op_call): Or op().

	* decl2.c (change_return_type): Fix 'this' quals.

From-SVN: r157681