Re-organize directory structure (#4971)

See discussion in #2491

Co-authored-by: Ivan Levkivskyi <ilevkivskyi@dropbox.com>

stdlib/fnmatch.pyi

@@ -0,0 +1,6 @@
+from typing import AnyStr, Iterable, List
+
+def fnmatch(name: AnyStr, pat: AnyStr) -> bool: ...
+def fnmatchcase(name: AnyStr, pat: AnyStr) -> bool: ...
+def filter(names: Iterable[AnyStr], pat: AnyStr) -> List[AnyStr]: ...
+def translate(pat: str) -> str: ...