Display other locations of Reused lint errors

Summary: It's not trivial to find them inside 700+ lines long functions.

Test Plan:
Linted `reused-iterators.lint-test` renamed to `_.php`, saw other locations.
Repeated for `reused-local.lint-test`.
Repeated for `duplicate-key-in-array.lint-test`.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Differential Revision: https://secure.phabricator.com/D4871