[llvm] [LoopPeel] prevent estimated trip count overflow before peel (PR #195610)

[Joel E. Denny via llvm-commits]

jdenny-ornl wrote:

> @jdenny-ornl addressed your changes. I have yet to have commit access, so can you merge it if possible?

Sure, but let's wait for pre-commit CI.  I'll try to check back tomorrow.

https://github.com/llvm/llvm-project/pull/195610