See rARC3ffed59bd7. Currently, when a unit test includes a syntax error, it is raised in an unclear way ("error at line 10, char 1: XHP1 Unknown lint message!").

This is because each test case only activates rules it wants to test, so we lose the ID/name for the syntax message. However, we always want to test this and the lint engine can always raise it.

To get a better error message, include it unconditionally. So a test for rule X really tests two rules: syntax, and X.

Ran arc unit at HEAD, got a better test failure:

   FAIL  ArcanistCallTimePassByReferenceXHPASTLinterRuleTestCase::testLinter
In 'call-time-pass-by-reference.lint-test', expected lint to raise error on line 10 at char 8, but no error was raised. Actually raised:
  error at line 10, char 1: XHP1 PHP Syntax Error!