Change the rename pass to be "tail recursive", only adding N-1 successors to the worklist, and handling the last one with a 'tail call'.  This speeds up PR1432 from 2.0578s to 2.0012s (2.8%)
Change the rename pass to be "tail recursive", only adding N-1 successors
to the worklist, and handling the last one with a 'tail call'.  This speeds
up PR1432 from 2.0578s to 2.0012s (2.8%)


git-svn-id: 0ff597fd157e6f4fc38580e8d64ab130330d2411@40822 91177308-0d34-0410-b5e6-96231b3b80d8

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