do not allow generators with type hints

moar tests

Author: krakjoe

Zend/tests/return_hint/013.phpt

@@ -14,6 +14,6 @@ class foo {
 $baz = new foo();
 var_dump($func=$baz->bar(), $func());
 ?>
---EXPECT--
-Fatal error: the function {closure} was expected to return array and returned null in %s on line %d
+--EXPECTF--
+Fatal error: the function %s was expected to return array and returned null in %s on line %d
 

Zend/tests/return_hint/014.phpt

@@ -0,0 +1,14 @@
+--TEST--
+Basic return hints no yield
+--FILE--
+<?php
+function foo() : array {
+	yield;
+}
+
+foo();
+?>
+--EXPECTF--
+Fatal error: The "yield" expression can not be used inside a function with a return type hint in %s on line %d
+
+

Zend/zend_compile.c

@@ -2893,6 +2893,10 @@ void zend_do_yield(znode *result, znode *value, const znode *key, zend_bool is_v
 	if (!CG(active_op_array)->function_name) {
 		zend_error_noreturn(E_COMPILE_ERROR, "The \"yield\" expression can only be used inside a function");
 	}
+	
+	if (CG(active_op_array)->return_hint.used) {
+		zend_error_noreturn(E_COMPILE_ERROR, "The \"yield\" expression can not be used inside a function with a return type hint");
+	}
 
 	CG(active_op_array)->fn_flags |= ZEND_ACC_GENERATOR;