Remove some hacks in the testing scripts & prepare for checked mode handling with kernel

tools/testing/dart/runtime_configuration.dart

 // Copyright (c) 2014, 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.
 
 library runtime_configuration;
 
 import 'dart:io' show Directory, File;
 
 import 'compiler_configuration.dart' show CommandArtifact;
 
@@ skipping 262 matching lines @@
       CommandBuilder commandBuilder,
       CommandArtifact artifact,
       List<String> arguments,
       Map<String, String> environmentOverrides) {
     String script = artifact.filename;
     String type = artifact.mimeType;
     if (script != null && type != 'application/dart-precompiled') {
       throw "dart_precompiled cannot run files of type '$type'.";
     }
 
-    var args = new List();
-    args.addAll(arguments);
-    for (var i = 0; i < args.length; i++) {
-      if (args[i].endsWith(".dart")) {
-        args[i] = "${artifact.filename}/out.aotsnapshot";
-      }
-    }
-
     return <Command>[
       commandBuilder.getVmCommand(suite.dartPrecompiledBinaryFileName,
-          args, environmentOverrides)
+          arguments, environmentOverrides)
     ];
   }
 }
 
 class DartPrecompiledAdbRuntimeConfiguration
       extends DartVmRuntimeConfiguration {
   final bool useBlobs;
   DartPrecompiledAdbRuntimeConfiguration({bool useBlobs}) : useBlobs = useBlobs;
 
   List<Command> computeRuntimeCommands(
@@ skipping 60 matching lines @@
 class DummyRuntimeConfiguration extends DartVmRuntimeConfiguration {
   List<Command> computeRuntimeCommands(
       TestSuite suite,
       CommandBuilder commandBuilder,
       CommandArtifact artifact,
       List<String> arguments,
       Map<String, String> environmentOverrides) {
     throw "Unimplemented runtime '$runtimeType'";
   }
 }