Revert "Fix updating packages map on reload and add a regression test"

runtime/bin/vmservice/loader.dart

Index: runtime/bin/vmservice/loader.dart
diff --git a/runtime/bin/vmservice/loader.dart b/runtime/bin/vmservice/loader.dart
index 87903850121a94738f6b78fd99b38cd4f9b7c1d8..6573e787a718b94792bd617a99273922d983d878 100644
--- a/runtime/bin/vmservice/loader.dart
+++ b/runtime/bin/vmservice/loader.dart
@@ -1033,9 +1033,9 @@ _processLoadRequest(request) {
         if (loaderState == null) {
           loaderState = new IsolateLoaderState(isolateId);
           isolateEmbedderData[isolateId] = loaderState;
+          loaderState.init(
+              packageRoot, packagesFile, workingDirectory, rootScript);
         }
-        loaderState.init(
-            packageRoot, packagesFile, workingDirectory, rootScript);
         loaderState.sp = sp;
         assert(isolateEmbedderData[isolateId] == loaderState);
       }