Add comment to IS_TYPE_UNINITIALIZED test

Author: iluuu1994

ext/reflection/tests/ReflectionMethod_getStaticVariables_basic_extra_bleed.phpt

@@ -10,11 +10,15 @@ function test() {
 
 function foo() {
     $methodInfo = new ReflectionFunction(__FUNCTION__);
-    $null = $methodInfo->getStaticVariables()['a'];
+    $nullWithIsTypeUninitialized = $methodInfo->getStaticVariables()['a'];
 
     static $a = test();
     var_dump($a);
-    $a = $null;
+
+    // Technically, IS_TYPE_UNINITIALIZED does bleed, but it doesn't matter since there's no way we
+    // can assign it to the static variable directly instead of the reference.
+    $staticVar = &$methodInfo->getStaticVariables()['a'];
+    $staticVar = $nullWithIsTypeUninitialized;
 }
 
 foo();