Add a linter rule for parentheses being used with PHP language constructs

Summary: Fixes T5648.

Test Plan: Added some test cases.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin

Maniphest Tasks: T5648

Differential Revision: https://secure.phabricator.com/D10122
Rename a test class

Summary: Rename `ArcanistPHPCSLinterTestCase` to `ArcanistPhpcsLinterTestCase` for consistency with the class being tested.

Test Plan: `arc unit`

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D10145
Patch: don't complain about reviewers not being specified.
This will break in the future when upstream arc incorporates T4631. Hopefully there will be a better solution by then