message: Rename CodegenUnit::work_product to previous_work_product
  It returns the previous work product or panics if there is none. This rename
  makes the purpose of this method clearer.
diff: @@ -85,7 +85,7 @@ fn reuse_workproduct_for_cgu(
  work_products: &mut FxHashMap<WorkProductId, WorkProduct>,
  ) -> CompiledModule {
  let mut object = None;
  - let work_product = cgu.work_product(tcx);
  + let work_product = cgu.previous_work_product(tcx);
  if let Some(saved_file) = &work_product.saved_file {
  let obj_out =
  tcx.output_filenames(()).temp_path(OutputType::Object, Some(cgu.name().as_str()));
  