Show all versions found when merging timing runs from different bench versions

Author: Geoffrey Broadwell

analyze

@@ -148,7 +148,7 @@ sub merge_timing_files {
                   run    => {
                              start_time => $start_time,
                              end_time   => $end_time,
-                             versions   => { bench => $versions[0] },
+                             versions   => { bench => join ', ' => @versions },
                             },
                   times  => [ map $times{$_}, @test_order ],
                  };