Re-organize directory structure (#4971)

See discussion in #2491

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

stdlib/spwd.pyi

@@ -0,0 +1,15 @@
+from typing import List, NamedTuple
+
+class struct_spwd(NamedTuple):
+    sp_namp: str
+    sp_pwdp: str
+    sp_lstchg: int
+    sp_min: int
+    sp_max: int
+    sp_warn: int
+    sp_inact: int
+    sp_expire: int
+    sp_flag: int
+
+def getspall() -> List[struct_spwd]: ...
+def getspnam(name: str) -> struct_spwd: ...