Merge branch 'ab/perf-installed-fix'

Performance test framework has been broken and measured the version
of Git that happens to be on $PATH, not the specified one to
measure, for a while, which has been corrected.

* ab/perf-installed-fix:
  perf-lib.sh: forbid the use of GIT_TEST_INSTALLED
  perf tests: add "bindir" prefix to git tree test results
  perf-lib.sh: remove GIT_TEST_INSTALLED from perf-lib.sh
  perf-lib.sh: make "./run <revisions>" use the correct gits
  perf aggregate: remove GIT_TEST_INSTALLED from --codespeed
  perf README: correct docs for 3c8f12c96c regression

diff --cc t/perf/aggregate.perl
index 76dd48f,b951747..66554d2
--- 1/t/perf/aggregate.perl
--- 2/t/perf/aggregate.perl
+++ b/t/perf/aggregate.perl
@@@ -3,8 -3,10 +3,9 @@@
  use lib '../../perl/build/lib';
  use strict;
  use warnings;
 -use JSON;
  use Getopt::Long;
  use Git;
+ use Cwd qw(realpath);
  
  sub get_times {
        my $name = shift;