Add test for GH-7821

Author: iluuu1994

Zend/tests/enum/gh8418.phpt

@@ -0,0 +1,20 @@
+--TEST--
+GH-8418: Enum constant expression evaluation doesn't work with warmed cache
+--FILE--
+<?php
+
+class ExampleClass
+{
+    public const EXAMPLE_CONST = 42;
+}
+
+enum ExampleEnum: int
+{
+    case ENUM_CASE = ExampleClass::EXAMPLE_CONST;
+}
+
+var_dump(ExampleEnum::ENUM_CASE->value);
+
+?>
+--EXPECT--
+int(42)