Does anyone know why the functionality of _PyObject_GC_Malloc isn't
available in a public function? I need to create a GCable object
whose size is computed at instance creation time, but which is not a
classic VAR_ object (it doesn't have an ob_size field).
Currently I call _PyObject_GC_Malloc directly, but I don't like the
dependence on a private API. If there is no good reason for keeping
gc_malloc private, I'd like to propose on python-dev that it be made
public as PyObject_GC_Malloc.