Add test file

Forgot to git add this.

Author: nikic

Zend/tests/nullsafe_operator/026.phpt

@@ -0,0 +1,26 @@
+--TEST--
+Nullsafe chain in static property / method name
+--FILE--
+<?php
+
+class Test {
+}
+
+$null = null;
+
+try {
+    Test::${$null?->foo}->bar;
+} catch (Error $e) {
+    echo $e->getMessage(), "\n";
+}
+
+try {
+    Test::{$null?->foo}()->bar;
+} catch (Error $e) {
+    echo $e->getMessage(), "\n";
+}
+
+?>
+--EXPECT--
+Access to undeclared static property Test::$
+Method name must be a string