Backport platform specific code to python2 (#6772)

stdlib/@python2/spwd.pyi

@@ -1,15 +1,16 @@
+import sys
 from typing import List, NamedTuple
 
-class struct_spwd(NamedTuple):
-    sp_nam: str
-    sp_pwd: 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: ...
+if sys.platform != "win32":
+    class struct_spwd(NamedTuple):
+        sp_nam: str
+        sp_pwd: 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: ...