Support use of dill in TypeEnv tests

tests/compiler/dart2js/kernel/mixin_test.dart

 // Copyright (c) 2017, 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.
 
 // Test that the optimized algorithm for mixin applications matches the mixins
 // generated by fasta.
 library dart2js.kernel.mixins_test;
 
 import 'package:async_helper/async_helper.dart';
 import 'package:compiler/src/commandline_options.dart';
@@ skipping 98 matching lines @@
     Uri entryPoint = await createTemp(Uri.parse('memory:main.dart'), SOURCE,
         printSteps: true);
 
     print(
         '---- compiler from ast -----------------------------------------------');
     var result =
         await runCompiler(entryPoint: entryPoint, options: [Flags.analyzeOnly]);
     Compiler compiler1 = result.compiler;
 
     Compiler compiler2 = await compileWithDill(
-        entryPoint, {}, [Flags.analyzeOnly],
+        entryPoint: entryPoint,
+        memorySourceFiles: {},
+        options: [Flags.analyzeOnly],
         printSteps: true);
 
     ElementEnvironment env1 = compiler1.frontendStrategy.elementEnvironment;
     DartTypes types1 = compiler1.frontendStrategy.dartTypes;
     ClosedWorld closedWorld1 = compiler1.resolutionWorldBuilder.closeWorld();
 
     KernelFrontEndStrategy frontendStrategy = compiler2.frontendStrategy;
     ElementEnvironment env2 = frontendStrategy.elementEnvironment;
     DartTypes types2 = frontendStrategy.dartTypes;
     ClosedWorld closedWorld2 = compiler2.resolutionWorldBuilder.closeWorld();
@@ skipping 62 matching lines @@
           '${cls1.name} direct subclasses',
           (a, b) => equivalence.entityEquivalence(a.cls, b.cls));
     }
 
     env1.forEachClass(env1.mainLibrary, (ClassEntity cls1) {
       ClassEntity cls2 = env2.lookupClass(env2.mainLibrary, cls1.name);
       checkClasses(cls1, cls2);
     });
   });
 }