Fix warnings in dart2js code and re-enable analyzer coverage.

sdk/lib/_internal/compiler/implementation/ssa/codegen.dart

 // Copyright (c) 2012, 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.
 
 part of ssa;
 
 class SsaCodeGeneratorTask extends CompilerTask {
 
   final JavaScriptBackend backend;
 
@@ skipping 2606 matching lines @@
 
   SsaUnoptimizedCodeGenerator(backend, work)
     : super(backend, work),
       oldBailoutSwitches = <js.Switch>[],
       newParameters = <js.Parameter>[],
       labels = <String>[],
       defaultClauseUsedInBailoutStack = <bool>[];
 
   String pushLabel() {
     String label = 'L${labelId++}';
-    labels.addLast(label);
+    labels.add(label);
     return label;
   }
 
   String popLabel() {
     return labels.removeLast();
   }
 
   String currentLabel() {
     return labels.last;
   }
@@ skipping 327 matching lines @@
   if (leftType.canBeNull() && rightType.canBeNull()) {
     if (left.isConstantNull() || right.isConstantNull() ||
         (leftType.isPrimitive() && leftType == rightType)) {
       return '==';
     }
     return null;
   } else {
     return '===';
   }
 }