Merge indirect call targets into hash tables by meta-data.

[pgoodman]

The idea here being that if we can show that two indirect edges have the same meta-data template, then their look-up lists can be merged. Combine this with conversion of a look-up list into a look-up table of lists, and there is something to this :-)

[pgoodman]

The major challenge here would likely be matching up the out-edge templates. Ultimately, I think the right way forward is to find some canonical way to deal with all indirect edges. This might involve making the in- and out-edges more strict.