[llvm] [VPlan] Remove VPPredInstPHIRecipe::useScalars (PR #143798)

[Luke Lau via llvm-commits]

lukel97 wrote:

> oh so this doesn't handle the case from [#142594 (comment)](https://github.com/llvm/llvm-project/pull/142594#discussion_r2140339682)?

No it doesn't cause that broadcast to be hoisted, the scalar VP operand is already outside of the loop body. 

That case in #142594 I guess just shows how the broadcast itself can be hoisted. But I don't think it's important if LICM is going to do it afterwards anyway

https://github.com/llvm/llvm-project/pull/143798