This code used to remove functions it no longer thinks are needed. That is, if it adds a legalized version of an import, it would remove the illegal one which is no longer needed. To avoid removing an illegal import that is still used it checked for ref.func appearances. But this was bad in two ways: We need to legalize the ref.funcs too. We can't call an illegal import in any way, not using a direct call, indirect call, or call by reference of a ref.func. It's silly to remove unneeded functions here. We have a pass for that. This removes the removal of functions, and adds proper updating of ref.calls, which means to call the stub function that looks like the original import, but that calls the legalized one and connects things up properly, exactly the same way as other calls. Also remove code that checked if we were in the stub/thunk and to not replace the call there. That code is not needed: no one will ever call the illegal import, so we do not need to be careful about preserving such calls.