build: make precompiled headers more useful

This can reduce the compilation time of a release
build (without tests) by more than 40%

Refs: #5212
Change-Id: I977aff0c0c7becbfee8a8b55605b81d0c014829b
diff --git a/tests/other/face-benchmark.cpp b/tests/other/face-benchmark.cpp
index c9a28b6..a81ba2c 100644
--- a/tests/other/face-benchmark.cpp
+++ b/tests/other/face-benchmark.cpp
@@ -28,7 +28,9 @@
 #include "face/tcp-channel.hpp"
 #include "face/udp-channel.hpp"
 
+#include <boost/asio/signal_set.hpp>
 #include <boost/exception/diagnostic_information.hpp>
+#include <boost/lexical_cast.hpp>
 
 #include <fstream>
 #include <iostream>