Add support for additional libraries to FE API

pkg/front_end/lib/kernel_generator.dart

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /// Defines the front-end API for converting source code to Dart Kernel objects.
 library front_end.kernel_generator;
 
 import 'compilation_error.dart';
 import 'compiler_options.dart';
 import 'dart:async';
@@ skipping 20 matching lines @@
 /// code for the SDK.
 ///
 /// If summaries are provided in [options], they may be used to speed up
 /// analysis. If in addition `compileSdk` is false, this will speed up
 /// compilation, as no source of the sdk will be generated.  Note however, that
 /// summaries for application code can also speed up analysis, but they will not
 /// take the place of Dart source code (since the Dart source code is still
 /// needed to access the contents of method bodies).
 Future<Program> kernelForProgram(Uri source, CompilerOptions options) async {
   var loader = await _createLoader(options, entry: source);
-  // TODO(sigmund): delete this. At this time we have no need to explicitly list
-  // VM libraries, since they are normally found by chasing dependencies.
-  // `dart:_builtin` is an exception because it is used by the kernel
-  // transformers to inform the VM about where the main entrypoint is. This is
-  // expected to change, and we should be able to remove these lines at that
-  // point. We check for the presense of `dart:developer` in the targetPatches
-  // to ensure we only load this library while running on the VM.
-  if (options.compileSdk &&
-      options.targetPatches.containsKey(Uri.parse('dart:developer'))) {
-    loader.loadLibrary(Uri.parse('dart:_builtin'));
+
+  if (options.compileSdk) {
+    options.additionalLibraries.forEach(loader.loadLibrary);
   }
+
   // TODO(sigmund): merge what we have in loadEverything and the logic below in
   // kernelForBuildUnit so there is a single place where we crawl for
   // dependencies.
   Program program = loader.loadProgram(source, compileSdk: options.compileSdk);
   _reportErrors(loader.errors, options.onError);
   return program;
 }
 
 /// Generates a kernel representation for a build unit.
 ///
@@ skipping 127 matching lines @@
 }
 
 // TODO(sigmund): delete this class. Dartk should not format errors itself, we
 // should just pass them along.
 class _DartkError implements CompilationError {
   String get correction => null;
   SourceSpan get span => null;
   final String message;
   _DartkError(this.message);
 }