[CostModel] Add CostKind argument to getShuffleCost

[CostModel] Add CostKind argument to getShuffleCost

Defaults to TCK_RecipThroughput - as most explicit calls were assuming TCK_RecipThroughput (vectorizers) or was just doing a before-vs-after comparison (vectorcombiner). Calls via getInstructionCost were just dropping the CostKind, so again there should be no change at this time (as getShuffleCost and its expansions don't use CostKind yet) - but it will make it easier for us to better account for size/latency shuffle costs in inline/unroll passes in the future.

Differential Revision: https://reviews.llvm.org/D132287