[PPC] Misscompilation due to pointer comparision

[vchuravy]

julia> div(-11, 2, RoundUp)
-4

Julia 1.5 works correctly so I suspect an LLVM bug.

[vchuravy]

Fixed by #38686

[JeffBezanson]

It's great, but how did that PR fix this? I thought it would only affect performance.

[vchuravy]

Filed upstream as https://bugs.llvm.org/show_bug.cgi?id=48388

[vchuravy]

Let's keep this open so that I don't loose track of it.

[JeffBezanson]

Wow that's a pretty crazy bug.

[vchuravy]

Proposed fix upstream https://reviews.llvm.org/D93092