Start using the partial tree reading in "git-diff-cache"
Start using the partial tree reading in "git-diff-cache"

The reason I say "start using" is that we really should also limit the
index checking by name - now we limit the tree object accesses by name,
but we still check the whole index.

Still, this should help.

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git