All strong mode cleaning of dart2js.

pkg/compiler/lib/src/constants/constant_constructors.dart

Index: pkg/compiler/lib/src/constants/constant_constructors.dart
diff --git a/pkg/compiler/lib/src/constants/constant_constructors.dart b/pkg/compiler/lib/src/constants/constant_constructors.dart
index 2da30e01bfa931fa6d6e2e531085b02c24a27684..d65b873952397dc568228af5fd0c199e4152d5b1 100644
--- a/pkg/compiler/lib/src/constants/constant_constructors.dart
+++ b/pkg/compiler/lib/src/constants/constant_constructors.dart
@@ -72,7 +72,7 @@ class ConstantConstructorComputer extends SemanticVisitor
     internalError(node, template.replaceFirst('#', '$node'));
   }
 
-  internalError(Node node, String message) {
+  internalError(Spannable node, String message) {
     throw new UnsupportedError(message);
   }