perf-test: add tests notmuch-git

The main focus of these initial tests is the (currently unacceptably
slow) checkout performance.

performance-test/T07-git.sh

@@ -0,0 +1,23 @@
+#!/usr/bin/env bash
+
+test_description='notmuch-git'
+
+. $(dirname "$0")/perf-test-lib.sh || exit 1
+
+time_start
+
+time_run 'init' "notmuch git init"
+
+time_run 'commit --force' "notmuch git commit --force"
+time_run 'commit' "notmuch git -l error commit"
+time_run 'commit' "notmuch git -l error commit"
+
+time_run 'checkout' "notmuch git checkout"
+
+time_run 'tag -inbox' "notmuch tag -inbox '*'"
+
+time_run 'checkout --force' "notmuch git checkout --force"
+
+
+
+time_done