[NFC] Fix a future PredictableMemOpt bug introduced by the previous commit.
This fixes a logic error that will only be exposed by the additional
functionality that motivated the cleanup. When the additional
functionality is checked in, it will contain a unit test for this fix.
This bug was introduced in:
commit 755a1467308be62090709fb1dec55a316faacd0f (public/predmem_rewrite)
Author: Andrew Trick <atrick@apple.com>
Date: Fri Sep 27 22:18:29 2024
[NFC] rewrite PredictableMemOpts dead allocation elimination