Add forgotten test

Author: nikic

Zend/tests/type_declarations/variance/enum_forward_compat.phpt

@@ -0,0 +1,26 @@
+--TEST--
+Forward compatibility with types that look like classes but aren't
+--FILE--
+<?php
+
+spl_autoload_register(function($class) {
+    var_dump($class);
+    if ($class === 'X') {
+        class X {}
+    } else {
+        class Y {}
+    }
+});
+
+class A {
+    public function method(X $param) : object {}
+}
+
+class B extends A {
+    public function method(object $param) : Y {}
+}
+
+?>
+--EXPECT--
+string(1) "Y"
+string(1) "X"