swift234

[sil-arc-opts] Teach the optimizer that certain instructions whose memory behavior is MayHaveSideEffects do not decrement ref counts.

The relevant instructions are:

1. DeallocStackInst.
2. StrongRetainInst.
3. StrongRetainAutoreleasedInst.
4. StrongRetainUnownedInst.
5. UnownedRetainInst.
6. PartialApplyInst.
7. CondFailInst.
8. CopyAddrInst when initialized.

Swift SVN r12639