Remove the global _Py_CheckRecursionLimit variable: it has been
replaced by ceval.recursion_limit of the PyInterpreterState
structure.
There is no need to keep the variable for the stable ABI, since
Py_EnterRecursiveCall() and Py_LeaveRecursiveCall() were not usable
in Python 3.8 and older: these macros accessed PyThreadState members,
whereas the PyThreadState structure is opaque in the limited C API.
This is partly a cleanup of the code. It also is preparation for getting the variables from the source (cross-platform) rather than from the symbols.
The change only touches the tool (and its tests).
The "Slot" helper (descriptor) is leaking references due to its caching mechanism. The change includes a partial fix to Slot, but also adds Variable.storage to replace the problematic use of Slot.
https://bugs.python.org/issue38187
Pablo Galindo
Victor Stinner
Serhiy Storchaka
Lysandros Nikolaou
AMIR
Eric Snow
Benjamin Peterson