[llvm] [VPlan] First step towards VPlan cost modeling. (PR #92555)

[Florian Hahn via llvm-commits]

fhahn wrote:

> from what I understand, cross compiling from x64 mac to arm64 mac isn't supported, you'd have to compile from an arm64 mac

Ah I forgot to mention that I saw the problem when building for arm64 on arm64 macOS, so no cross compiling (it fails both with and without `target_cpu = "arm64"`)

https://github.com/llvm/llvm-project/pull/92555