Use an approach suggested by Tamar in https://github.com/dotnet/runtime/issues/43789#issuecomment-716492368 Also see follow up in https://github.com/dotnet/runtime/issues/43789#issuecomment-786993244 We should investigate if we can use `DC ZCA` for `genCodeForInitBlkUnroll` when `src->IsIntegralConst(0)` in the same fashion as it is done in #46609 cc @dotnet/jit-contrib @TamarChristinaArm