* decl.c (xref_basetypes): Refactor.
* tree.c (copy_base_binfos): Replace with ...
(copy_binfo): ... this. Deep copy the given binfo, (not the just
bases of the given base).
* cp-tree.h (copy_base_binfo): Remove.
(copy_binfo): Declare.
From-SVN: r84758
