This macro calls the function @xref{modu_Init} to reset the module interface to point to the original functions.
External modules are allowed to alter the support function table implementing their own functions and thus altering the behavior of other extensions. These extensions usually set some of the entries of the support function table to point to functions implemented in the external module. However these functions are available only so long as long the extension is in memory. When the extension is exiting the pointers should be restored. Otherwise it may happen that the extension is already unloaded and the function is used by another module exiting later.
Because there is no guaranteed order of extension module unload the modules should call this function to restore the support function table and should not rely on altered function calls during module exit code is executed.