[llvm] [DAG] visitFREEZE - replace multiple frozen/unfrozen uses of an SDValue with just the frozen node (PR #150017)

[Nikita Popov via llvm-commits]

https://github.com/nikic approved this pull request.

This looks reasonable to me, but I only had a cursory look through the test diffs.

https://github.com/llvm/llvm-project/pull/150017