Added stub for dircache(py2) (#1510)

stdlib/2/dircache.pyi

@@ -0,0 +1,10 @@
+# Source: https://hg.python.org/cpython/file/2.7/Lib/dircache.py
+
+from typing import List, MutableSequence, Text, Union
+
+def reset() -> None: ...
+def listdir(path: Text) -> List[str]: ...
+
+opendir = listdir
+
+def annotate(head: Text, list: Union[MutableSequence[str], MutableSequence[Text], MutableSequence[Union[str, Text]]]) -> None: ...