[CostModel][X86] getArithmeticInstrCost - use cost kind specific look up tables

Building on D132216, use CostKindTblEntry cost tables to simplify the transition to supporting cost kinds other than recip-throughput

Adding full cost kinds support is going to take a while, but by converting to CostKindTblEntry first it will make it easier to support the costs on a per-ISD basis.