Added bad examples from RFC

Author: morrisonlevi

Zend/tests/return_hint/rfc001.phpt

@@ -0,0 +1,16 @@
+--TEST--
+Description: returned type does not match the type declaration
+
+--FILE--
+<?php
+
+function get_config(): array {
+    return 42;
+}
+
+
+--EXPECTF--
+Fatal error: the function get_config was expected to return an array and returned an integer in %s on line 4
+
+
+

Zend/tests/return_hint/rfc002.phpt

@@ -0,0 +1,14 @@
+--TEST--
+Int is not a valid type declaration
+
+--FILE--
+<?php
+
+function answer(): int {
+    return 42;
+}
+
+--EXPECTF--
+Fatal error: the function answer was expected to return an object of class int and returned an integer in %s on line 4
+
+

Zend/tests/return_hint/rfc003.phpt

@@ -0,0 +1,14 @@
+--TEST--
+Cannot return null with a return type declaration
+
+--FILE--
+<?php
+
+function foo(): bar {
+    return null;
+}
+
+--EXPECTF--
+Fatal error: the function foo was expected to return an object of class bar and returned null in %s on line 4
+
+

Zend/tests/return_hint/rfc004.phpt

@@ -0,0 +1,21 @@
+--TEST--
+Missing return type on override
+
+--FILE--
+<?php
+
+class User {}
+
+interface UserGateway {
+    function find($id) : User; 
+}
+
+class UserGateway_MySql implements UserGateway {
+    // must return User or subtype of User
+    function find($id) {
+        return new User;
+    } 
+}
+
+--EXPECTF--
+Fatal error: Delcaration of UserGateway_MySql::find should be compatible with UserGateway::find($id) : User, return type missing in %s on line 9

Zend/tests/return_hint/rfc005.phpt

@@ -0,0 +1,16 @@
+--TEST--
+Cannot define a return type on a Generator
+
+--FILE--
+<?php
+
+function filter(Traversable $in, callable $filter): array {
+    foreach ($in as $key => $value) {
+        if ($filter($key, $value)) {
+            yield $key => $value;
+        }
+    }
+}
+
+--EXPECTF--
+Fatal error: The "yield" expression can not be used inside a function with a return type hint in %s on line 6