Function addwrapper 

pub fn addwrapper(table: &modulestab, modname: &str, w: funcwrap) -> i32

Port of addwrapper(Module m, FuncWrap w) from Src/module.c:577. Returns 0 on add, 1 on clash. Walks WRAPPERS for an existing entry with the same handler; appends if absent and sets WRAPF_ADDED on the input record.