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

[Patrick O'Neill via llvm-commits]

patrick-rivos wrote:

I haven't bisected the issue but from the discussion looks like this fuzzer find might be related:
https://github.com/llvm/llvm-project/issues/96328

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