Restore __deserialize_content optimization

serde_core/src/lib.rs

@@ -261,6 +261,15 @@ pub use crate::ser::{Serialize, Serializer};
 
 #[doc(hidden)]
 pub use lib::from_utf8_lossy;
+
+// Used by generated code. Not public API.
+#[cfg(all(not(no_serde_derive), any(feature = "std", feature = "alloc")))]
+#[doc(hidden)]
+#[path = "private.rs"]
+pub mod __private;
+#[cfg(all(not(no_serde_derive), any(feature = "std", feature = "alloc")))]
+use self::__private as private;
+
 #[path = "de/seed.rs"]
 mod seed;