When Python cannot report an error and its is not possible to recover from the error, Py_FatalError() displays an error message and exit immediately Python.

It's common that Python crashes are coming from third party extension modules, rather than Python itself. Recent example: bpo-42891 crash reported in Python, but it was a bug in lsm-db third party extension module.

I propose to enhance Py_FatalError() to attempt to dump the list of extension modules, to ease debugging.

I'm working on a PR.