Generator expression without parenthesis does not raise SyntaxError

Feature

In CPython, generator expression without parenthesis raises following error

>>> foo(x, z for z in range(10), t, w)
  File "<stdin>", line 1
    foo(x, z for z in range(10), t, w)
           ^^^^^^^^^^^^^^^^^^^^
SyntaxError: Generator expression must be parenthesized

However, In RustPython, it does not matter

>>>>> foo(x, z for z in range(10), t, w)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
NameError: name 'foo' is not defined

Python Documentation

首先重現 issue 中的兩個生成器表達式範例，並追蹤它們在 RustPython Parser 專案中的處理方式。完成的標準是：帶有額外引數且未加括號的生成器表達式會引發文件所述的 SyntaxError，同時有效的生成器表達式仍能繼續被正確解析。