[llvm] SCEV: thread samesign in isBasicBlockEntryGuardedByCond (NFC) (PR #125840)

[Nico Weber via llvm-commits]

nico wrote:

You're right, it cycled green on the next build (http://45.33.8.238/macm1/100557/summary.html). If this is a known flake:

* Is there an issue filed for it?
* Should we mark the test as `UNSUPPORTED` on aarch64 until it's no longer flaky?

https://github.com/llvm/llvm-project/pull/125840