Make Exception a class, not an interface, and remove the const constructor.

sdk/lib/html/scripts/systemhtml.py

Index: sdk/lib/html/scripts/systemhtml.py
diff --git a/sdk/lib/html/scripts/systemhtml.py b/sdk/lib/html/scripts/systemhtml.py
index dbdb4ccaa29d86cc75e6e1df969ab95cedf3030b..4106f4df5a302e9cc5429c5186321a5ed8858868 100644
--- a/sdk/lib/html/scripts/systemhtml.py
+++ b/sdk/lib/html/scripts/systemhtml.py
@@ -766,7 +766,7 @@ class Dart2JSBackend(HtmlDartGenerator):
             GenerateChecksAndCall(operation, position)
         GenerateChecksAndCall(operation, len(operation.arguments))
       body.Emit(
-          '    throw const Exception("Incorrect number or type of arguments");'
+          '    throw new ArgumentError("Incorrect number or type of arguments");'
           '\n');
     else:
       operation = operations[0]