[3.9] bpo-41690: Use a loop to collect args in the parser instead of recursion (GH-22053) by pablogsal · Pull Request #22067 · python/cpython

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…recursion (pythonGH-22053)

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 <Pablogsal@gmail.com>