Rewrite to use the reachability cloner interface.  Also, make this much more efficient in the case where a function calls into the same graph multiple times (ie, it either contains multiple calls to the same function, or multiple calls to functions in the same SCC graph)
Rewrite to use the reachability cloner interface.  Also, make this much more
efficient in the case where a function calls into the same graph multiple times
(ie, it either contains multiple calls to the same function, or multiple calls
to functions in the same SCC graph)


git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@10986 91177308-0d34-0410-b5e6-96231b3b80d8

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