Remove deprecated parts of dart:async.

sdk/lib/_internal/compiler/implementation/dart2js.dart

Index: sdk/lib/_internal/compiler/implementation/dart2js.dart
diff --git a/sdk/lib/_internal/compiler/implementation/dart2js.dart b/sdk/lib/_internal/compiler/implementation/dart2js.dart
index e30543a8ea85a4bd8db1d64dd710c1a3115c2991..4ad188feb8c9ad8b619b7a8b626a158a7f22983f 100644
--- a/sdk/lib/_internal/compiler/implementation/dart2js.dart
+++ b/sdk/lib/_internal/compiler/implementation/dart2js.dart
@@ -590,7 +590,7 @@ void helpAndFail(String message) {
 }
 
 void mainWithErrorHandler(Options options) {
-  runZoned(() => compilerMain(options), onError: (exception) {
+  runZoned(() => compilerMain(options), onError: (exception, trace) {
     try {
       print('Internal error: $exception');
     } catch (ignored) {
@@ -598,7 +598,6 @@ void mainWithErrorHandler(Options options) {
     }
 
     try {
-      var trace = getAttachedStackTrace(exception);
       if (trace != null) {
         print(trace);
       }