use monomorphic `compare` in enum maps
use monomorphic `compare` in enum maps

Reviewed By: dsainati1

Differential Revision: D21549730

fbshipit-source-id: 81793ff0d543ba4d2c2b21b1998d7a6eeb81a501

mroch/flow,facebook/flow,facebook/flow,mroch/flow,facebook/flow,facebook/flow,mroch/flow,mroch/flow,facebook/flow,mroch/flow,facebook/flow,mroch/flow,mroch/flow,facebook/flow