[syntax-errors] Store to or delete __debug__ (#16984)

Summary
--

Detect setting or deleting `__debug__`. Assigning to `__debug__` was a
`SyntaxError` on the earliest version I tested (3.8). Deleting
`__debug__` was made a `SyntaxError` in [BPO 45000], which said it was
resolved in Python 3.10. However, `del __debug__` was also a runtime
error (`NameError`) when I tested in Python 3.9.6, so I thought it was
worth including 3.9 in this check.

I don't think it was ever a *good* idea to try `del __debug__`, so I
think there's also an argument for not making this version-dependent at
all. That would only simplify the implementation very slightly, though.

[BPO 45000]: https://github.com/python/cpython/issues/89163

Test Plan
--

New inline tests. This also required adding a `PythonVersion` field to
the `TestContext` that could be taken from the inline `ParseOptions` and
making the version field on the options accessible.

crates/ruff_python_parser/resources/inline/err/debug_shadow_class.py

@@ -0,0 +1,2 @@
+class __debug__: ...  # class name
+class C[__debug__]: ...  # type parameter name

crates/ruff_python_parser/resources/inline/err/debug_shadow_function.py

@@ -0,0 +1,3 @@
+def __debug__(): ...  # function name
+def f[__debug__](): ...  # type parameter name
+def f(__debug__): ...  # parameter name

crates/ruff_python_parser/resources/inline/err/debug_shadow_import.py

@@ -0,0 +1,4 @@
+import __debug__
+import debug as __debug__
+from x import __debug__
+from x import debug as __debug__

crates/ruff_python_parser/resources/inline/err/debug_shadow_match.py

@@ -0,0 +1,2 @@
+match x:
+    case __debug__: ...

crates/ruff_python_parser/resources/inline/err/debug_shadow_try.py

@@ -0,0 +1,2 @@
+try: ...
+except Exception as __debug__: ...

crates/ruff_python_parser/resources/inline/err/debug_shadow_type_alias.py

@@ -0,0 +1,2 @@
+type __debug__ = list[int]  # visited as an Expr but still flagged
+type Debug[__debug__] = str

crates/ruff_python_parser/resources/inline/err/debug_shadow_with.py

@@ -0,0 +1 @@
+with open("foo.txt") as __debug__: ...

crates/ruff_python_parser/resources/inline/err/del_debug_py39.py

@@ -0,0 +1,2 @@
+# parse_options: {"target-version": "3.9"}
+del __debug__

crates/ruff_python_parser/resources/inline/err/write_to_debug_expr.py

@@ -0,0 +1,4 @@
+del __debug__
+del x, y, __debug__, z
+__debug__ = 1
+x, y, __debug__, z = 1, 2, 3, 4

crates/ruff_python_parser/resources/inline/ok/debug_rename_import.py

@@ -0,0 +1,3 @@
+import __debug__ as debug
+from __debug__ import Some
+from x import __debug__ as debug

crates/ruff_python_parser/resources/inline/ok/del_debug_py38.py

@@ -0,0 +1,2 @@
+# parse_options: {"target-version": "3.8"}
+del __debug__

crates/ruff_python_parser/resources/inline/ok/read_from_debug.py

@@ -0,0 +1,2 @@
+if __debug__: ...
+x = __debug__