message: use prettier printing
diff: @@ -545,7 +545,7 @@ trait EvalContextPrivExt<'a, 'mir, 'tcx: 'a+'mir>: crate::MiriEvalContextExt<'a,
  let this = self.eval_context_mut();
  let protector = if protect { Some(this.frame().extra) } else { None };
  let ptr = place.ptr.to_ptr()?;
  - trace!("reborrow: {:?} reference {} derived from {} (pointee {}): {:?}, size {}",
  + trace!("reborrow: {} reference {} derived from {} (pointee {}): {:?}, size {}",
  kind, new_tag, ptr.tag, place.layout.ty, ptr, size.bytes());
  // Get the allocation. It might not be mutable, so we cannot use `get_mut`.
  