Start unraveling circularities between analyzer and front_end/kernel.

pkg/kernel/test/baseline_tester.dart

 // Copyright (c) 2016, 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.
 import 'dart:io';
 
-import 'package:kernel/analyzer/loader.dart';
+import 'package:analyzer/src/kernel/loader.dart';
 import 'package:kernel/application_root.dart';
 import 'package:kernel/kernel.dart';
 import 'package:kernel/target/targets.dart';
 import 'package:kernel/text/ast_to_text.dart';
 import 'package:kernel/verifier.dart';
 import 'package:path/path.dart' as pathlib;
 import 'package:test/test.dart';
 
 final String testcaseDirectory = 'pkg/kernel/testcases';
 final String inputDirectory = 'pkg/kernel/testcases/input';
@@ skipping 63 matching lines @@
                 '  rm $filenameOfBaseline\n'
                 'Command to see the diff:\n'
                 '  diff -cd $outputDirectory/$shortName.{baseline,current}.txt'
                 '\n');
           }
         }
       });
     }
   }
 }