fixup! Use size_t instead of int for sizes and trip counts.

src/lib/work-stealing.c

@@ -316,7 +316,7 @@ Work* execute_pure_loop(
   int grain_size = 1;
   if (end_iter - start_iter <= grain_size) {
     // Few enough iterations; just do them.
-    for (int i = start_iter; i < end_iter; i++) {
+    for (size_t i = start_iter; i < end_iter; i++) {
       do_work(thread_id, body(thread_id, i, env));
     }
     return join_work(cont);