Better test262 test procedure

.test262/uncull

@@ -0,0 +1,10 @@
+#!/bin/bash
+
+if [ ! -d data/test/suite.base ]
+then
+    echo "Can't uncull because \"./data/test/suite.base\" is missing"
+    exit 64
+fi
+
+rm -rf data/test/suite
+mv data/test/suite.base data/test/suite