[LV] Change getSmallBestKnownTC to return an ElementCount (NFC)#141793

paulwalker-arm merged 2 commits intollvm:mainllvm/llvm-project:mainfrom

paulwalker-arm:lv-vscale-based-tc-loops-refactorpaulwalker-arm/llvm-project:lv-vscale-based-tc-loops-refactorCopy head branch name to clipboard