Experiment with new function-type syntax.

pkg/compiler/lib/src/dart2js.dart

Index: pkg/compiler/lib/src/dart2js.dart
diff --git a/pkg/compiler/lib/src/dart2js.dart b/pkg/compiler/lib/src/dart2js.dart
index 9ee75e9b6f606c78119c5e75fff3ed671ddc7fb8..3ec6836fd632079f2ee9a128baf0d55694199119 100644
--- a/pkg/compiler/lib/src/dart2js.dart
+++ b/pkg/compiler/lib/src/dart2js.dart
@@ -40,7 +40,7 @@ String BUILD_ID = null;
  * string argument, or the arguments iterator for multiple arguments
  * handlers.
  */
-typedef void HandleOption(data);
+typedef HandleOption = (dynamic data) -> void;
 
 class OptionHandler {
   final String pattern;
@@ -760,12 +760,12 @@ void main(List<String> arguments) {
   internalMain(arguments);
 }
 
-typedef void ExitFunc(int exitCode);
-typedef Future<api.CompilationResult> CompileFunc(
+typedef ExitFunc = (int exitCode) -> void;
+typedef CompileFunc = (
     CompilerOptions compilerOptions,
     api.CompilerInput compilerInput,
     api.CompilerDiagnostics compilerDiagnostics,
-    api.CompilerOutput compilerOutput);
+    api.CompilerOutput compilerOutput) -> Future<api.CompilationResult>;
 
 ExitFunc exitFunc = exit;
 CompileFunc compileFunc = api.compile;