Let phutil_rebuild_map **really** be quiet

Summary: Depends on D9586. The progress bar is written to stderr which results in bad stuff happening when you try run `lint` (`PhutilLibraryLinter` calls it)

Test Plan: run `arc lint`, see no more errors

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D9587