[llvm] [EarlyIfConversion] Extend data dependent analysis across multiple blocks (PR #180623)

[Nathan Corbyn via llvm-commits]

cofibrant wrote:

> Is it possible there's a loop between the load and the compare? How does the heuristic handle that?

This is also a good point: I would guess the fix is just to check if any of the blocks we visit in `callInRange()` lives in a tighter loop and bail out if so?

https://github.com/llvm/llvm-project/pull/180623