Add test cases for sys._jit

Author: lambda-abstraction

stdlib/@tests/test_cases/sys/check_jit.py

@@ -0,0 +1,10 @@
+import sys
+from typing_extensions import assert_type
+
+if sys.version_info >= (3, 14):
+    assert_type(sys._jit.is_available(), bool)
+    assert_type(sys._jit.is_enabled(), bool)
+    assert_type(sys._jit.is_active(), bool)
+
+    # sys is not a package, so this should be an error
+    import sys._jit # type: ignore