swift234

[arc] Sink the re-running of ARC opts with frozen epilogue releases further into ARCSequenceOpts so that the loop visitor does not need to have any special handling for ARCSequenceOpts.

Previously, we would outside of ARCSequenceOpts, run ARCSequenceOpts twice with
a flag set in one case and a flag unset in the other case. Now ARCSequenceOpts
internally performs these two runs of the optimization.