[llvm] InferAddressSpaces: Handle prefetch intrinsic (PR #101982)

[Matt Arsenault via llvm-commits]

arsenm wrote:

### Merge activity

* **Aug 5, 4:10 PM EDT**: @arsenm started a stack merge that includes this pull request via [Graphite](https://app.graphite.dev/github/pr/llvm/llvm-project/101982).


https://github.com/llvm/llvm-project/pull/101982