tree 2a0270be597a62ec49db69b128e5afb12aa00d67
parent e924de52950c871d34d8e734a8eabb5620490219
author Shawn Pearce <spearce@spearce.org> 1499128259 -0700
committer Shawn Pearce <spearce@spearce.org> 1500304537 -0700

Use separate DfsStreamKey for PackIndex

Instead of overloading the pack's DfsStreamKey with negative positions
for the idx, reverse idx and bitmap, assign a unique DfsStreamKey for
each of these related streams.

Change-Id: Ie048036c74a1d1bbf5ea7e888452dc0c1adf992f