Remove another import-related `Loc.btwn` from `statement.ml`
Remove another import-related `Loc.btwn` from `statement.ml`

Summary: We need to get rid of these for abstract locations to work.

Reviewed By: jbrown215

Differential Revision: D12959887

fbshipit-source-id: 030af8a9abb43335a5000f197732e6a5078ff510

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