Add test for yielding short function.

Author: Crell

Zend/tests/short_functions/short-generator.phpt

@@ -0,0 +1,19 @@
+--TEST--
+Short functions that yield.
+--FILE--
+<?php
+
+function read($it): iterable => yield from $it;
+
+$a = [1, 2, 3];
+
+print_r(iterator_to_array(read($a)));
+
+?>
+--EXPECT--
+Array
+(
+    [0] => 1
+    [1] => 2
+    [2] => 3
+)