Use hyperfine in the benchmark driver if available

benchmarks/driver.sh

@@ -1,4 +1,4 @@
-#!/bin/sh
+#!/usr/bin/env bash
 
 if [ "$#" -ne 1 ]; then
     echo "Usage: driver.sh /path/to/fish"
@@ -10,5 +10,8 @@ BENCHMARKS_DIR=$(dirname "$0")/benchmarks
 for benchmark in "$BENCHMARKS_DIR"/*; do
     echo $(basename "$benchmark")
     ${FISH_PATH} --print-rusage-self $benchmark > /dev/null
+    if hash hyperfine 2>/dev/null; then
+        hyperfine "${FISH_PATH} $benchmark > /dev/null"
+    fi
 done