PyOS_AfterFork_Child() helper functions now return a PyStatus:
PyOS_AfterFork_Child() is now responsible to handle errors.
* Move _PySignal_AfterFork() to the internal C API
* Add #ifdef HAVE_FORK on _PyGILState_Reinit(), _PySignal_AfterFork()
and _PyInterpreterState_DeleteExceptMain().
In the experimental isolated subinterpreters build mode, the GIL is
now per-interpreter.
Move gil from _PyRuntimeState.ceval to PyInterpreterState.ceval.
new_interpreter() always get the config from the main interpreter.
Move recursion_limit member from _PyRuntimeState.ceval to
PyInterpreterState.ceval.
* Py_SetRecursionLimit() now only sets _Py_CheckRecursionLimit
of ceval.c if the current Python thread is part of the main
interpreter.
* Inline _Py_MakeEndRecCheck() into _Py_LeaveRecursiveCall().
* Convert _Py_RecursionLimitLowerWaterMark() macro into a static
inline function.