When a Python thread has no frame, _Py_DumpTraceback() and
_Py_DumpTracebackThreads() now write "<no Python frame>", rather than
writing nothing.

(cherry picked from commit 8fa3e17)

_PyObject_Dump() now dumps the object address for freed objects and
objects with ob_type=NULL.

(cherry picked from commit b39afb7)

Add _PyRuntimeState.preinitializing field: set to 1 while
Py_PreInitialize() is running.

_PyRuntimeState: rename also pre_initialized field to preinitialized.

(cherry picked from commit d3b9041)

(cherry picked from commit 1ce16fb)