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

[Alexander Kornienko via llvm-commits]

alexfh wrote:

Luckily, the code involved is open-source (a part of https://chromium.googlesource.com/angle/angle). Here's the non-reduced IR dump I got using `clang -mllvm -print-before=loop-vectorize -mllvm -print-module-scope`: [err3.tar.gz](https://github.com/user-attachments/files/16257109/err3.tar.gz)


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