re PR c++/10990 (Cannot convert with dynamic_cast<> to a private base class from within a member function)

	PR c++/10990
	* search.c (lookup_base_r): Rely on accessible_p, rather than
	trying to emulate that logic here.

	PR c++/10990
	* g++.dg/rtti/dyncast1.C: New test.
	* g++.dg/abi/mangle4.C: Correct base-specifier access.
	* g++.dg/lookup/scoped1.C: Remove XFAIL.
	* g++.old-deja/g++.martin/pmf1.C: Correct base-specifier access.

From-SVN: r68507