CI: thread dump on benchmark timeout (see #462, #457)

Each benchmark is now run like this:

    timeout --signal=SIGQUIT 5m java ...

Thus threads are dumped on timeout which should help debugging.

tools/ci/bench-base.sh

@@ -6,5 +6,5 @@ java -jar "$RENAISSANCE_JAR" --raw-list > list.txt
 
 for BENCH in $(cat list.txt); do
 	echo "====> $BENCH"
-	java -Xms2500M -Xmx2500M -jar "$RENAISSANCE_JAR" -c test -r 1 --csv output.csv --json output.json "$BENCH" || exit 1
+	timeout_with_thread_dump 5m java -Xms2500M -Xmx2500M -jar "$RENAISSANCE_JAR" -c test -r 1 --csv output.csv --json output.json "$BENCH" || exit 1
 done

tools/ci/bench-standalone.sh

@@ -8,5 +8,5 @@ unzip "$RENAISSANCE_JAR" -d "extracted-renaissance"
 
 for BENCH in $(cat list.txt); do
 	echo "====> $BENCH"
-	java -Xms2500M -Xmx2500M -jar "./extracted-renaissance/single/$BENCH.jar" -c test -r 1 --csv output.csv --json output.json "$BENCH" || exit 1
+	timeout_with_thread_dump 5m java -Xms2500M -Xmx2500M -jar "./extracted-renaissance/single/$BENCH.jar" -c test -r 1 --csv output.csv --json output.json "$BENCH" || exit 1
 done

tools/ci/common.sh

@@ -67,6 +67,23 @@ get_jvm_workaround_args() {
     esac
 }
 
+if command -v timeout >/dev/null; then
+    TIMEOUT_IMPL=timeout_with_thread_dump_real
+else
+    TIMEOUT_IMPL=timeout_with_thread_dump_fake
+fi
+
+timeout_with_thread_dump_real() {
+    timeout --signal=3 --kill-after=5s "$@"
+}
+timeout_with_thread_dump_fake() {
+    shift
+    "$@"
+}
+timeout_with_thread_dump() {
+    "$TIMEOUT_IMPL" "$@"
+}
+
 
 # Make sure we are in the top-level directory so that we can use
 # relative paths when referring to files within the project.