Add reflection test

Author: nikic

ext/reflection/tests/static_type.phpt

@@ -0,0 +1,23 @@
+--TEST--
+ReflectionType for static types
+--FILE--
+<?php
+
+class A {
+    public function test(): static {
+        return new static;
+    }
+}
+
+$rm = new ReflectionMethod(A::class, 'test');
+$rt = $rm->getReturnType();
+// TODO: Should it be considered a builtin or not?
+var_dump($rt->isBuiltin());
+var_dump($rt->getName());
+var_dump((string) $rt);
+
+?>
+--EXPECT--
+bool(true)
+string(6) "static"
+string(6) "static"