Add canonicalization test

Author: nikic

Zend/tests/restrict_globals/key_canonicalization.phpt

@@ -0,0 +1,11 @@
+--TEST--
+$GLOBALS should have canonicalized keys
+--FILE--
+<?php
+
+${1} = 42;
+var_dump($GLOBALS[1]);
+
+?>
+--EXPECT--
+int(42)