Finish strong mode cleaning of dart2js.

pkg/compiler/lib/src/ssa/variable_allocator.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.
 
 import '../common.dart';
 import '../js_backend/js_backend.dart';
 import 'nodes.dart';
 
 /**
  * The [LiveRange] class covers a range where an instruction is live.
@@ skipping 225 matching lines @@
   //     t3 = check(t2)
   //     t4 = use(t3)
   //     t5 = use(t3)
   //     t6 = use(t2)
   //
   // The t1 is generate-at-use site, and the live-range must thus be on t2 and
   // not on the checked instruction t1.
   // When looking for the checkedInstructionOrNonGenerateAtUseSite of t3 we must
   // return t2.
   HInstruction checkedInstructionOrNonGenerateAtUseSite(HCheck check) {
-    var checked = check.checkedInput;
+    dynamic checked = check.checkedInput;
     while (checked is HCheck) {
       HInstruction next = checked.checkedInput;
       if (generateAtUseSite.contains(next)) break;
       checked = next;
     }
     return checked;
   }
 
   void markAsLiveInEnvironment(
       HInstruction instruction, LiveEnvironment environment) {
@@ skipping 448 matching lines @@
       if (!needsName(input)) {
         names.addAssignment(predecessor, input, phi);
       } else {
         names.addCopy(predecessor, input, phi);
       }
     }
 
     namer.allocateName(phi);
   }
 }