This code doesn't have effect on the final result, but causes
GCC 8 warnings and can have an undefined behavior.
(cherry picked from commit 827d49f3cf)
* group the (stateful) runtime globals into various topical structs
* consolidate the topical structs under a single top-level _PyRuntimeState struct
* add a check-c-globals.py script that helps identify runtime globals
Other globals are excluded (see globals.txt and check-c-globals.py).
* fixed OrderedDict.__init__ docstring re PEP 468
* tightened comment and mirrored to C impl
* added space after period per marco-buttu
* preserved substituted for stable
* drop references to Python 3.6 and PEP 468
* Indent versionchanged at method level, not class level
* Mark up ``--help`` to avoid generating an en dash
* Use forward slash in Unix command line with a dollar sign ($) prompt
Issue #28858: The change b9c9691c72c5 introduced a regression. It seems like
_PyObject_CallArg1() uses more stack memory than
PyObject_CallFunctionObjArgs().
* PyObject_CallFunctionObjArgs(func, NULL) => _PyObject_CallNoArg(func)
* PyObject_CallFunctionObjArgs(func, arg, NULL) => _PyObject_CallArg1(func, arg)
PyObject_CallFunctionObjArgs() allocates 40 bytes on the C stack and requires
extra work to "parse" C arguments to build a C array of PyObject*.
_PyObject_CallNoArg() and _PyObject_CallArg1() are simpler and don't allocate
memory on the C stack.
This change is part of the fastcall project. The change on listsort() is
related to the issue #23507.
