re PR c++/40139 (ICE on invalid use of destructor)

re PR c++/40139 (ICE on invalid use of destructor)

	PR c++/40139
	* pt.c (tsubst_qualified_id): Retain the type if we aren't dealing
	with a dependent type.  Actually look up the destructor.
	* semantics.c (finish_id_expression): Fix logic.
	(finish_qualified_id_expr): Don't try to use 'this' if we aren't in
	a function.
	* typeck.c (build_x_unary_op): Diagnose taking the address of a
	constructor or destructor.
	* tree.c (get_first_fn): Handle OFFSET_REF.

From-SVN: r147638