Verify closures can access $this

Author: thekid

src/test/php/lang/ast/unittest/emit/InitializeWithExpressionsTest.class.php

@@ -50,6 +50,19 @@ public function run() {
     Assert::equals(new Handle(1), $r(new Handle(0)));
   }
 
+  #[Test]
+  public function using_closures_referencing_this() {
+    $r= $this->run('use lang\ast\unittest\emit\Handle; class <T> {
+      private $id= 1;
+      private $h= fn() => new Handle($this->id);
+
+      public function run() {
+        return $this->h;
+      }
+    }');
+    Assert::equals(new Handle(1), $r());
+  }
+
   #[Test]
   public function using_anonymous_classes() {
     $r= $this->run('class <T> {