* class.c (build_simple_base_path): New fn.
(build_base_path): Use it for non-virtual base references.
(layout_class_type): Change base fields to their real type
after layout is done.
* cp-tree.h (IS_FAKE_BASE_TYPE): New macro.
* cp-lang.c (cxx_get_alias_set): Use it.
From-SVN: r81349
