[llvm] [LV] Bundle sub reductions into VPExpressionRecipe (PR #147255)

[Florian Hahn via llvm-commits]

fhahn wrote:

(not sure why, but it looks like the precommit tests on Linux/Windows have not been triggered for some reason, but the libx++ ones have; may be solve by updating the latest main again?)

https://github.com/llvm/llvm-project/pull/147255