Unimpl Serialize for AValueImpl and BlackHole

Summary: Some old dead code.

Reviewed By: ndmitchell

Differential Revision: D56378816

fbshipit-source-id: 46b9c9eae1aff0642e7401a94a05f3c89ac1b593

starlark/src/values/layout/avalue.rs

@@ -24,8 +24,6 @@ use std::mem;
 
 use allocative::Allocative;
 use derive_more::Display;
-use serde::Serialize;
-use serde::Serializer;
 use starlark_syntax::slice_vec_ext::SliceExt;
 
 use crate as starlark;
@@ -686,24 +684,6 @@ where
 #[display(fmt = "BlackHole")]
 pub(crate) struct BlackHole(pub(crate) ValueAllocSize);
 
-impl Serialize for BlackHole {
-    fn serialize<S>(&self, _s: S) -> Result<S::Ok, S::Error>
-    where
-        S: Serializer,
-    {
-        panic!()
-    }
-}
-
-impl<'v, Mode: AValueMode, T: StarlarkValue<'v>> Serialize for AValueImpl<Mode, T> {
-    fn serialize<S>(&self, s: S) -> Result<S::Ok, S::Error>
-    where
-        S: Serializer,
-    {
-        erased_serde::serialize(&self.1, s)
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use crate::environment::Module;

starlark/src/values/layout/vtable.rs

@@ -174,10 +174,7 @@ impl AValueVTable {
                 let this = unsafe { &*this.value_ptr::<BlackHole>() };
                 this as *const dyn Debug
             },
-            erased_serde_serialize: |this| {
-                let this = unsafe { &*this.value_ptr::<BlackHole>() };
-                this as *const dyn erased_serde::Serialize
-            },
+            erased_serde_serialize: |_this| unreachable!(),
             allocative: |this| {
                 let this = unsafe { &*this.value_ptr::<BlackHole>() };
                 this as *const dyn Allocative