Tests for `void`.

pkg/compiler/lib/src/js_backend/runtime_types.dart

Index: pkg/compiler/lib/src/js_backend/runtime_types.dart
diff --git a/pkg/compiler/lib/src/js_backend/runtime_types.dart b/pkg/compiler/lib/src/js_backend/runtime_types.dart
index e6e5a5d4faf752bc5c0ffdd7f04806f3e228feef..be4f9666980fa2909662f1394440b7ea162a4fbd 100644
--- a/pkg/compiler/lib/src/js_backend/runtime_types.dart
+++ b/pkg/compiler/lib/src/js_backend/runtime_types.dart
@@ -898,6 +898,9 @@ class TypeRepresentationGenerator implements DartTypeVisitor {
   }
 
   visitVoidType(ResolutionVoidType type, _) {
+    jsAst.Expression name =
+        getJavaScriptClassName(backend.backendClasses.voidClass);
+    return type.treatAsRaw ? name : visitList(type.typeArguments, head: name);
     // TODO(ahe): Reify void type ("null" means "dynamic").
     return js('null');
   }