Merge branch 'sb/perf-without-installed-git' into maint

Performance-measurement tests did not work without an installed Git.

* sb/perf-without-installed-git:
  t/perf: make runner work even if Git is not installed

Author: gitster

t/perf/aggregate.perl

@@ -1,5 +1,6 @@
 #!/usr/bin/perl
 
+use lib '../../perl/blib/lib';
 use strict;
 use warnings;
 use Git;