[llvm] [SLP]Fix graph traversal in getSpillCost (PR #124984)

[Alexey Bataev via llvm-commits]

alexey-bataev wrote:

> Hm, I may have noticed one other thing. I think you want to replace "&*PrevInstIt != PrevInst" with !isVectorized(&*PrevInstIt) in the NumCall++ condition. It doesn't seem to cause a measurable test diff in tree, but I think the current code could over-count calls which are all part of one vector bundle.
> 
> This change applied on it's own to the prior version of the code causes the same changes in the tests as this review. So it's not purely a nop.

Added the check for non-vectorized/vectorized as function call calls

https://github.com/llvm/llvm-project/pull/124984