Improve linter rule for useless overriding methods

Summary: Ref T7409. This linter rule was added in D12419, but fails in some specific cases. Improve the handling of `n_DECLARATION_PARAMETER_LIST`.

Test Plan: Added unit tests.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: Korvin, epriestley

Maniphest Tasks: T7409

Differential Revision: https://secure.phabricator.com/D12828

src/lint/linter/ArcanistXHPASTLinter.php

@@ -3788,9 +3788,13 @@ final class ArcanistXHPASTLinter extends ArcanistBaseXHPASTLinter {
       $parameters = array();
 
       foreach ($parameter_list->getChildren() as $parameter) {
-        $parameters[] = $parameter
-          ->getChildOfType(1, 'n_VARIABLE')
-          ->getConcreteString();
+        $parameter = $parameter->getChildByIndex(1);
+
+        if ($parameter->getTypeName() == 'n_VARIABLE_REFERENCE') {
+          $parameter = $parameter->getChildOfType(0, 'n_VARIABLE');
+        }
+
+        $parameters[] = $parameter->getConcreteString();
       }
 
       $statements = $method->getChildByIndex(5);

src/lint/linter/__tests__/xhpast/useless-overriding-method.lint-test

@@ -12,8 +12,13 @@ final class MyClass extends SomeOtherClass {
   public function usefulMethod($x, array $y) {
     return parent::usefulMethod($x, null);
   }
+
+  public function anotherMethod($x, &$y) {
+    return parent::anotherMethod($x, $y);
+  }
 }
 ~~~~~~~~~~
 error:3:13
 advice:4:3
 advice:8:3
+advice:16:3