Provide alternative enum attribute in case it starts with a digit
@creiter
Submitted by Christoph Reiter Link to original bug (#768471)
Description
https://mail.gnome.org/archives/gir-devel-list/2016-July/msg00000.html
Example:
There exists a GLib.SpawnError.2BIG which should be accessible under GLib.SpawnError._2BIG
https://docs.python.org/3/reference/lexical_analysis.html#identifiers