(save_tree_status): Function_maybepermanent_obstack is the function_obstack
of parent function.
(restore_tree_status): Only free objects later than maybepermanent_firstobj in
function_maybepermanent_obstack.
(make_node): Fix logic error in PARM_DECL code.
Put PARM_DECL in parent function's saveable obstack.

From-SVN: r5713