Split js_backend_cps_ir tests into multiple test units.

tests/compiler/dart2js/js_backend_cps_ir.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.
-// VMOptions=-DUSE_CPS_IR=true
 
 // Test that the CPS IR code generator compiles programs and produces the
 // the expected output.
 
 import 'package:async_helper/async_helper.dart';
 import 'package:expect/expect.dart';
 import 'package:compiler/src/apiimpl.dart'
        show Compiler;
 import 'memory_compiler.dart';
 import 'package:compiler/src/js/js.dart' as js;
 import 'package:compiler/src/common.dart' show Element;
 
-import 'js_backend_cps_ir_basic.dart' as basic;
-import 'js_backend_cps_ir_literals.dart' as literals;
-import 'js_backend_cps_ir_operators.dart' as operators;
-import 'js_backend_cps_ir_control_flow.dart' as control_flow;
-import 'js_backend_cps_ir_interceptors.dart' as interceptors;
-import 'js_backend_cps_ir_closures.dart' as closures;
-
 const String TEST_MAIN_FILE = 'test.dart';
 
-List<TestEntry> tests = <TestEntry>[]
-     ..addAll(basic.tests)
-     ..addAll(literals.tests)
-     ..addAll(control_flow.tests)
-     ..addAll(operators.tests)
-     ..addAll(interceptors.tests)
-     ..addAll(closures.tests);
-
 class TestEntry {
   final String source;
   final String expectation;
   const TestEntry(this.source, [this.expectation]);
 }
 
 String formatTest(Map test) {
   return test[TEST_MAIN_FILE];
 }
 
 String getCodeForMain(Compiler compiler) {
   Element mainFunction = compiler.mainFunction;
   js.Node ast = compiler.enqueuer.codegen.generatedCode[mainFunction];
   return js.prettyPrint(ast, compiler).getText();
 }
 
-main() {
+
+runTests(List<TestEntry> tests) {
   Expect.isTrue(const bool.fromEnvironment("USE_CPS_IR"));
 
   for (TestEntry test in tests) {
     Map files = {TEST_MAIN_FILE: test.source};
     asyncTest(() {
       Compiler compiler = compilerFor(files);
       Uri uri = Uri.parse('memory:$TEST_MAIN_FILE');
       return compiler.run(uri).then((bool success) {
         Expect.isTrue(success);
         String expectation = test.expectation;
         if (expectation != null) {
           String expected = test.expectation;
           String found = getCodeForMain(compiler);
           if (expected != found) {
             Expect.fail('Expected:\n$expected\nbut found\n$found');
           }
         }
       }).catchError((e) {
         print(e);
         Expect.fail('The following test failed to compile:\n'
                     '${formatTest(files)}');
       });
     });
   }
 }