545ce5b6e0
Similar to normal change refs, meta refs are not tag-able. Excluding them from the list of interesting refs in TagSet scales down on the amount of work we have to do later on when calculating tags. The fewer references we have prior to calculating the tags, the less memory we'll need when using BitSets to deal with refs flags. Change-Id: Idc3308e3378bfede57d95cd65457129484385794