[llvm] [LoopCacheAnalysis] Fix loop cache cost to always round the cost up to the nearest integer number (PR #88915)

[Chen Zheng via llvm-commits]

chenzheng1030 wrote:

> I didn't see anything in the PPC LIT changes that I think is alarming. I think this is okay.

Thanks for checking, Roland.

https://github.com/llvm/llvm-project/pull/88915