Add most equivalence tests to js_model/model_test

tests/compiler/dart2js/js_model/model_test.dart

Index: tests/compiler/dart2js/js_model/model_test.dart
diff --git a/tests/compiler/dart2js/js_model/model_test.dart b/tests/compiler/dart2js/js_model/model_test.dart
index 329d1f162b8c2e807861b63af3173aebcc94b2f7..a557f641b90de5a234f3461f5540286fdd7533dc 100644
--- a/tests/compiler/dart2js/js_model/model_test.dart
+++ b/tests/compiler/dart2js/js_model/model_test.dart
@@ -4,14 +4,8 @@
 
 import 'dart:async';
 import 'package:async_helper/async_helper.dart';
-import 'package:compiler/src/commandline_options.dart';
-import 'package:compiler/src/common.dart';
-import 'package:compiler/src/compiler.dart';
 import 'package:compiler/src/kernel/kernel_backend_strategy.dart';
-import 'package:compiler/src/js_model/js_strategy.dart';
-import 'package:expect/expect.dart';
 import '../kernel/compile_from_dill_test_helper.dart';
-import '../kernel/compiler_helper.dart';
 import '../serialization/helper.dart';
 
 main(List<String> args) {
@@ -41,15 +35,12 @@ Future mainInternal(List<String> args,
       print(test.sources.values.first);
       print('----------------------------------------------------------------');
     }
-
-    enableDebugMode();
-
-    Compiler compiler1 = await compileWithDill(test.entryPoint, test.sources, [
-      Flags.disableInlining,
-      Flags.disableTypeInference
-    ], beforeRun: (Compiler compiler) {
-      compiler.backendStrategy = new JsBackendStrategy(compiler);
-    }, printSteps: true);
-    Expect.isFalse(compiler1.compilationFailed);
+    await runTest(test.entryPoint, test.sources,
+        verbose: arguments.verbose,

[Siggi Cherem (dart-lang), 2017/07/05 21:25:53]

I think I'm missing something: with this change I don't see where you create the
JsBackendStrategy?

[Johnni Winther, 2017/07/06 14:53:40]

By `useJsStrategyForTesting = true;` in line 12.

[Siggi Cherem (dart-lang), 2017/07/06 17:47:46]

Ah! thanks, indeed that's what I missed. I recall when you added it, but missed
that the line overriding JsBackendStrategy here (the `beforeRun` on the left)
was probably not necessary anymore, correct?

[Johnni Winther, 2017/07/07 08:23:50]

Yes. I just forgot to remove it earlier.

+        skipWarnings: skipWarnings,
+        skipErrors: skipErrors,
+        options: options,
+        expectAstEquivalence: false,
+        expectIdenticalOutput: false);
   }
 }