ALocSet and ALocMap
ALocSet and ALocMap

Summary: There are lots of places that currently use `LocSet` and `LocMap`. We've previously rationalized `ALoc.compare`.

Reviewed By: jbrown215

Differential Revision: D10414263

fbshipit-source-id: 49920958add784c41755c6067a873299e2053570

nmote/flow,nmote/flow,nmote/flow,nmote/flow,nmote/flow,nmote/flow,nmote/flow