[llvm] [LV] Consider whether vscale is a known power of two for iteration check (PR #144963)

[Luke Lau via llvm-commits]

lukel97 wrote:

> I don't believe this is possible to test on a target without scalable vector support. I tried, but the costs returned are all invalid, and thus we refuse to vectorize entirely. 

Does `-force-target-instruction-cost=1` help?

https://github.com/llvm/llvm-project/pull/144963