Remove "TB" unit tests

Summary: These fail on 32-bit machines and seem not valuable enough to try to make work with bc, etc.

Test Plan: Ran tests (depends on D2622).

Reviewers: floatinglomas, vrana, btrahan

Reviewed By: vrana

CC: aran

Maniphest Tasks: T1298

Differential Revision: https://secure.phabricator.com/D2623