Added new test

Zend/tests/foreach_008.phpt

@@ -0,0 +1,21 @@
+--TEST--
+Nested foreach by reference and array modification
+--FILE--
+<?php
+$a = [0, 1, 2, 3];
+foreach ($a as &$x) {
+	foreach ($a as &$y) {
+		echo "$x - $y\n";
+		if ($x == 0 && $y == 1) {
+			unset($a[2]);
+			unset($a[1]);
+		}
+	}
+}
+?>
+--EXPECT--
+0 - 0
+0 - 1
+0 - 3
+3 - 0
+3 - 3