Restore compatibility with rustc 1.13.0

error[E0432]: unresolved import `private::de::size_hint`
      --> src/de/value.rs:28:5
       |
    28 | use private::de::size_hint;
       |     ^^^^^^^^^^^^^^^^^^^^^^ Maybe a missing `extern crate private`?

serde/src/de/impls.rs

@@ -7,11 +7,11 @@ use de::{
 #[cfg(any(core_duration, feature = "std", feature = "alloc"))]
 use de::MapAccess;
 
+use __private::de::InPlaceSeed;
 use de::from_primitive::FromPrimitive;
-use private::de::InPlaceSeed;
 
 #[cfg(any(feature = "std", feature = "alloc"))]
-use private::de::size_hint;
+use __private::de::size_hint;
 
 ////////////////////////////////////////////////////////////////////////////////
 

serde/src/de/value.rs

@@ -24,8 +24,8 @@
 use lib::*;
 
 use self::private::{First, Second};
+use __private::de::size_hint;
 use de::{self, Expected, IntoDeserializer, SeqAccess};
-use private::de::size_hint;
 use ser;
 
 ////////////////////////////////////////////////////////////////////////////////

serde/src/lib.rs

@@ -273,6 +273,7 @@ pub mod __private;
 
 #[allow(unused_imports)]
 use self::__private as export;
+#[allow(unused_imports)]
 use self::__private as private;
 
 #[cfg(not(feature = "std"))]