Assign anonymous class to a variable in the tests

As suggested during code review

Co-authored-by: Juliette <[email protected]>

Author: rodrigoprimo

src/Standards/Generic/Tests/CodeAnalysis/UselessOverridingMethodUnitTest.1.inc

@@ -126,7 +126,7 @@ function shouldBailEarly() {
     parent::shouldBailEarly();
 }
 
-new class extends ParentClass {
+$anon = new class extends ParentClass {
     public function uselessOverridingMethod() {
         parent::uselessOverridingMethod();
     }
@@ -138,7 +138,7 @@ new class extends ParentClass {
 };
 
 function foo() {
-    new class extends ParentClass {
+    $anon = new class extends ParentClass {
         public function uselessOverridingMethod() {
             parent::uselessOverridingMethod();
         }