c++: make finish_non_static_data_member SFINAE enabled [PR105351]

Here since finish_non_static_data_member isn't SFINAE enabled, we
incorrectly emit an error when considering the first overload rather
than silently discarding it:

sfinae33.C: In substitution of ‘template<class T> A<T::value> f() [with T = B]’:
sfinae33.C:11:7:   required from here
sfinae33.C:5:31: error: invalid use of non-static data member ‘B::value’
    5 | template<class T> A<T::value> f();
      |                               ^

This patch makes the function SFINAE enabled in the usual way: give it a
complain parameter, check it before emitting an error, and pass it through
appropriately.

	PR c++/105351

gcc/cp/ChangeLog:

	* cp-tree.h (finish_non_static_data_member): Add defaulted
	complain parameter.
	* pt.cc (tsubst_copy_and_build): Pass complain to
	finish_non_static_data_member.
	* semantics.cc (finish_non_static_data_member): Respect complain
	parameter.
	(finish_qualified_id_expr): Pass complain to
	finish_non_static_data_member.

gcc/testsuite/ChangeLog:

	* g++.dg/template/sfinae33.C: New test.