"""
The [1] thing is used in more places:

 PyObject *f_localsplus[1]; in PyFrameObject
 PyObject *ob_item[1]; in PyTupleObject
 void *elements[1]; in asdl_seq and int elements[1];` in asdl_int_seq
 digit ob_digit[1]; in PyLongObject
 Py_ssize_t ob_array[1]; in PyMemoryViewObject
 _tracemalloc.c: frame_t frames[1]; in traceback_t

Do we need to update all of them? Do you want to update them all?
""" - vstinner

I believe we probably do.  But I suggest multiple PRs.  I'll update the issue title.

I'm also going to ask clang/llvm folks that prompted me to look into this for comments.