Include missing header and fix old absl alias.
Include missing header and fix old absl alias.

PiperOrigin-RevId: 274188202

iree-org/iree,iree-org/iree,iree-org/iree,google/iree,google/iree,google/iree,iree-org/iree,google/iree,iree-org/iree,google/iree,iree-org/iree,iree-org/iree,google/iree,google/iree