* cp-tree.h (BV_USE_VCALL_INDEX_P): New macro.
	(BV_GENERATE_THUNK_WITH_VTABLE_P): Likewise.
	(lang_decl_flags): Add generate_with_vtable_p.  Make vcall_offset
	a tree, not an int.
	(THUNK_GENERATE_WITH_VTABLE_P): New macro.
	(make_thunk): Change prototype.
	(emit_thunk): Rename to use_thunk.
	(mangle_thunk): Change prototype.
	* class.c (get_derived_offset): Simplify.
	(copy_virtuals): Clear BV_USE_VCALL_INDEX_P and
	BV_GENERATE_THUNK_WITH_VTABLE_P.
	(build_primary_vtable): Simplify.
	(add_virtual_function): Use BV_FN, rather than TREE_VALUE.
	(dfs_find_base): Remove.
	(update_vtable_entry_for_fn): Correct bug in finding the base
	where a virtual function was first declared.  Figure out whether
	or not to emit a vcall-thunk with the vtables in which it appears.
	Correct logic for deciding whether to use an ordinary thunk, or a
	vcall thunk.
	(finish_struct_1): Remove unnecssary code.
	(build_vtbl_initializer): Use ssize_int for the running counter of
	negative indices.
	(build_vtbl_initializer): Only use vcall thunks where necessary.
	Mark thunks as needing to be emitted with their vtables, or not.
	(build_vbase_offset_vtbl_entries): Adjust for use of ssize_int in
	indices.  Use size_binop.
	(dfs_build_vcall_offset_vtbl_entries): Don't rely on
	BINFO_PRIMARY_MARKED_P here.  Use BV_FN consistently.  Use
	size_binop.
	(build_rtti_vtbl_entries): Adjust call to build_vtable_entry.
	(build_vtable_entry): Mark thunks as needing to be emitted with
	their vtables, or not.
	* decl.c (lang_mark_tree): Mark the vcall_offset in a thunk.
	* decl2.c (mark_vtable_entries): Use use_thunk instead of
	emit_thunk.
	* dump.c (dequeue_and_dump): Remove dead code.  Dump new thunk
	information.
	* error.c (dump_expr): Use BV_FN.
	* mangle.c (mangle_thunk): Adjust now that vcall_offset is a tree,
	not an int.
	* method.c (make_thunk): Likewise.
	(emit_thunk): Rename to use_thunk.  Allow callers to decide
	whether or not to actually emit the thunk.  Adjust for changes in
	representation of vcall offsets.
	* search.c (dfs_get_pure_virtuals): Use BV_FN.
	* semantics.c (emit_associated_thunks): New function.
	(expand_body): Use it.
	* ir.texi: Adjust decriptions of thunks.

From-SVN: r34656