Repository: RustPython/RustPython (language: rust)

Issue:
allow `from __future__ import generator_stop`
## Feature

<!-- What Python feature is missing from RustPython? Give a short description of the feature and how you ran into its absence. -->

code:
```python
from __future__ import generator_stop
```

Expected: Nothing

Actual: SyntaxError: future feature generator_stop is not defined


## TODO

Add it to `compile_future_features` function

allow `from __future__ import generator_stop`
## Feature

<!-- What Python feature is missing from RustPython? Give a short description of the feature and how you ran into its absence. -->

code:
```python
from __future__ import generator_stop
```

Expected: Nothing

Actual: SyntaxError: future feature generator_stop is not defined


## TODO

Add it to `compile_future_features` function



Discussion / hints:

Fix patch:
diff --git a/compiler/codegen/src/compile.rs b/compiler/codegen/src/compile.rs
index 9f4f3df82f..7b912f43d2 100644
--- a/compiler/codegen/src/compile.rs
+++ b/compiler/codegen/src/compile.rs
@@ -2904,8 +2904,7 @@ impl Compiler {
             match feature.name.as_str() {
                 // Python 3 features; we've already implemented them by default
                 "nested_scopes" | "generators" | "division" | "absolute_import"
-                | "with_statement" | "print_function" | "unicode_literals" => {}
-                // "generator_stop" => {}
+                | "with_statement" | "print_function" | "unicode_literals" | "generator_stop" => {}
                 "annotations" => self.future_annotations = true,
                 other => {
                     return Err(self.error(CodegenErrorType::InvalidFutureFeature(other.to_owned())))


Test patch:
diff --git a/Lib/test/test_contextlib.py b/Lib/test/test_contextlib.py
index a9612c424f..71215ecf5d 100644
--- a/Lib/test/test_contextlib.py
+++ b/Lib/test/test_contextlib.py
@@ -197,8 +197,6 @@ class StopIterationSubclass(StopIteration):
                 else:
                     self.fail(f'{stop_exc} was suppressed')
 
-    # TODO: RUSTPYTHON
-    @unittest.expectedFailure
     def test_contextmanager_except_pep479(self):
         code = """\
 from __future__ import generator_stop