[llvm] [PPC] Set minimum of largest number of comparisons to use bit test for switch lowering (PR #155910)

[Shimin Cui via llvm-commits]

scui-ibm wrote:

> Buildbot is failing with a real error. (Not sure why it's only triggering on the aarch64 bot.)
> 
> Does this have any effect on non-PPC targets by default? Or is MaxBitTestEntry always at least 2?
> 
> Otherwise LGTM

Ooops! Thanks. It's an unused variable left in the code. Now all checks have passed.

https://github.com/llvm/llvm-project/pull/155910