* Add _PyRuntime.pre_initialized: set to 1 when Python
is pre-initialized
* Add _Py_PreInitialize() and _Py_PreInitializeFromPreConfig().
* _PyCoreConfig_Read() now calls _Py_PreInitialize().
* Move _PyPreConfig_GetGlobalConfig() and
_PyCoreConfig_GetGlobalConfig() calls from main.c to preconfig.c
and coreconfig.c.
* Revert "bpo-36097: Use only public C-API in the_xxsubinterpreters module (adding as necessary). (#12003)"
This reverts commit bcfa450f21.
* Revert "bpo-33608: Simplify ceval's DISPATCH by hoisting eval_breaker ahead of time. (gh-12062)"
This reverts commit bda918bf65.
* Revert "bpo-33608: Use _Py_AddPendingCall() in _PyCrossInterpreterData_Release(). (gh-12024)"
This reverts commit b05b711a2c.
* Revert "bpo-33608: Factor out a private, per-interpreter _Py_AddPendingCall(). (GH-11617)"
This reverts commit ef4ac967e2.