Merge the Sky Engine changes from the SkyDart branch

sky/tests/modules/import-without-export.sky

Index: sky/tests/modules/import-without-export.sky
diff --git a/sky/tests/modules/import-without-export.sky b/sky/tests/modules/import-without-export.sky
index a3eaa1ffe4cc4f98682073c0b11bcc3ea70ada1e..93a694fca395f68a6097484bff9e23095755606b 100644
--- a/sky/tests/modules/import-without-export.sky
+++ b/sky/tests/modules/import-without-export.sky
@@ -3,9 +3,10 @@
 <import src="../resources/dump-as-text.sky" />
 <div id="result">FAIL - Script did not execute</div>
 <script>
-var result = "FAIL";
-if (typeof hello === "object" && Object.keys(hello).length === 0)
-  result = "PASS";
-document.getElementById("result").textContent = result;
+import "dart:sky";
+
+void main() {
+    document.getElementById("result").textContent = "PASS";
+}
 </script>
 </html>