Fix native extensions located in packages on Windows.

runtime/bin/builtin.dart

Index: runtime/bin/builtin.dart
diff --git a/runtime/bin/builtin.dart b/runtime/bin/builtin.dart
index cb3691aa8d7763703b4d5fe4f0177b70de113c1c..92bbb90be7f831b73d6fe072db8384450279cff4 100644
--- a/runtime/bin/builtin.dart
+++ b/runtime/bin/builtin.dart
@@ -216,14 +216,13 @@ String _resolveUri(String base, String userString) {
     // Relative URIs with scheme dart-ext should be resolved as if with no
     // scheme.
     resolved = baseUri.resolve(uri.path);
-    var path = resolved.path;
     if (resolved.scheme == 'package') {
       // If we are resolving relative to a package URI we go directly to the
       // file path and keep the dart-ext scheme. Otherwise, we will lose the
       // package URI path part.
-      path = _filePathFromPackageUri(resolved);
+      resolved = new Uri.file(_filePathFromPackageUri(resolved));

[kustermann, 2014/01/28 21:58:38]

I thought you can have package roots which are HTTP urls. Which means, that you
would need to fetch the .so/.dll file and store it in a temporary place and load
it then.

If you can have HTTP urls as package-roots then this is broken!

[Bill Hesse, 2014/01/28 22:55:40]

Yes.  It was also broken earlier, but I have changed the CL to include a check.

     }
-    resolved = new Uri(scheme: 'dart-ext', path: path);
+    resolved = new Uri(scheme: 'dart-ext', path: resolved.path);
   } else {
     resolved = baseUri.resolve(userString);
   }