CODE_OWNERS: Assign Max to all other overlays

The Apple framework overlays are still owned by their respective teams
at Apple, but Max is the person to contact if you need to make a
change there. Actual /additions/ should still be considered feature
requests that should go to Apple's bug tracker (bugreport.apple.com).

CODE_OWNERS.TXT

@@ -52,6 +52,11 @@ E: [email protected]
 G: rjmccall
 D: Demangler, IRGen, Runtime
 
+N: Max Moiseev
+E: [email protected]
+G: moiseev
+D: Apple contact for non-corelibs overlays
+
 N: Tony Parker
 E: [email protected]
 G: parkera