Add scripts for running perf and callgrind.

scripts/perf.bash

@@ -0,0 +1,18 @@
+#!/usr/bin/env bash
+#
+set -euo pipefail
+IFS=$'\n\t'
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+: ${PROFILE:="perf"}
+
+cd "$DIR/../"
+
+cargo build --profile "$PROFILE" --no-default-features
+perf record --freq=2000 --call-graph dwarf --output=perf.data target/${PROFILE}/compare
+# Convert to a format firefox will read
+# flags to consider --show-info
+perf script -F +pid --input perf.data > perf.firefox
+
+echo "You probably want to go to https://profiler.firefox.com/"
+echo "Either that or run hotspot"