Implement spend_cpu_cycles in assembly

The compiler was unrolling it previously, so we're doing assembly now for consistency.

src/http_handler.hpp

@@ -88,7 +88,7 @@ struct HttpHandler : ConnectionHandler {
     resolveThread = std::thread{[this]() {
       pthread_setname_np(pthread_self(), "txn-resolve");
       for (;;) {
-        auto guard = commitPipeline.acquire<1, 0>();
+        auto guard = commitPipeline.acquire<1, 0>(/*maxBatch*/ 1);
         if (process_resolve_batch(guard.batch)) {
           return; // Shutdown signal received
         }