remove unnecessary buffer operations

Author: cyrgani

library/proc_macro/src/bridge/client.rs

@@ -294,9 +294,6 @@ fn run_client<A: for<'a, 's> Decode<'a, 's, ()>, R: Encode<()>>(
 
         let output = state::set(&state, || f(input));
 
-        // Take the `cached_buffer` back out, for the output value.
-        buf = RefCell::into_inner(state).cached_buffer;
-
         // HACK(eddyb) Separate encoding a success value (`Ok(output)`)
         // from encoding a panic (`Err(e: PanicMessage)`) to avoid
         // having handles outside the `bridge.enter(|| ...)` scope, and
@@ -306,7 +303,6 @@ fn run_client<A: for<'a, 's> Decode<'a, 's, ()>, R: Encode<()>>(
         // this is defensively trying to avoid any accidental panicking
         // reaching the `extern "C"` (which should `abort` but might not
         // at the moment, so this is also potentially preventing UB).
-        buf.clear();
         Ok::<_, ()>(output).encode(&mut buf, &mut ());
     }))
     .map_err(PanicMessage::from)