[llvm] [VPlan] Implement VPWidenCallRecipe::computeCost (NFCI). (PR #106047)

[Florian Hahn via llvm-commits]

fhahn wrote:

@mstorsjo thanks, should be fixed by dd94537b40cfb8c480df27c08fc715ce91ba4089

@antmox  @DavidSpickett AFAICT now the bots with Flang crashes should be back to green?

https://github.com/llvm/llvm-project/pull/106047