[3.9] bpo-41690: Use a loop to collect args in the parser instead of recursion (GH-22053)

[pablogsal]

…

This program can segfault the parser by stack overflow:

import ast code = "f(" + ",".join(['a' for _ in range(100000)]) + ")" print("Ready!") ast.parse(code) 

the reason is that the rule for arguments has a simple recursion when collecting args:

args[expr_ty]:
[...]
| a=named_expression b=[',' c=args{c }]{
[...] }.
(cherry picked from commit 4a97b15)

Co-authored-by: Pablo Galindo [email protected]

https://bugs.python.org/issue41690