c++: unresolved overload with comma op [PR115430]

c++: unresolved overload with comma op [PR115430]

This works:

  template<typename T>
  int Func(T);
  typedef int (*funcptrtype)(int);
  funcptrtype fp0 = &Func<int>;

but this doesn't:

  funcptrtype fp2 = (0, &Func<int>);

because we only call resolve_nondeduced_context on the LHS (via
convert_to_void) but not on the RHS, so cp_build_compound_expr's
type_unknown_p check issues an error.

	PR c++/115430

gcc/cp/ChangeLog:

	* typeck.cc (cp_build_compound_expr): Call resolve_nondeduced_context
	on RHS.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp0x/noexcept41.C: Remove dg-error.
	* g++.dg/overload/addr3.C: New test.