Turn the "no saved object file in work product" ICE into a translatable fatal error

compiler/rustc_codegen_ssa/src/errors.rs

@@ -121,6 +121,12 @@ pub struct NoNatvisDirectory {
     pub error: Error,
 }
 
+#[derive(Diagnostic)]
+#[diag(codegen_ssa_no_saved_object_file)]
+pub struct NoSavedObjectFile<'a> {
+    pub cgu_name: &'a str,
+}
+
 #[derive(Diagnostic)]
 #[diag(codegen_ssa_copy_path_buf)]
 pub struct CopyPathBuf {