Small changes to get the compilation size of code importing dart:html shorter.

lib/compiler/implementation/ssa/nodes.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.
 
 interface HVisitor<R> {
   R visitAdd(HAdd node);
   R visitBailoutTarget(HBailoutTarget node);
   R visitBitAnd(HBitAnd node);
   R visitBitNot(HBitNot node);
   R visitBitOr(HBitOr node);
@@ skipping 2260 matching lines @@
   bool typeEquals(other) => other is HStaticStore;
   bool dataEquals(HStaticStore other) => element == other.element;
   bool isStatement(HTypeMap types) => true;
 }
 
 class HLiteralList extends HInstruction {
   HLiteralList(inputs) : super(inputs);
   toString() => 'literal list';
   accept(HVisitor visitor) => visitor.visitLiteralList(this);
 
-  HType get guaranteedType() => HType.MUTABLE_ARRAY;
+  HType get guaranteedType() => HType.EXTENDABLE_ARRAY;
 
   void prepareGvn(HTypeMap types) {
     assert(!hasSideEffects(types));
   }
 }
 
 class HIndex extends HInvokeStatic {
   HIndex(HStatic target, HInstruction receiver, HInstruction index)
       : super(<HInstruction>[target, receiver, index]);
   toString() => 'index operator';
@@ skipping 459 matching lines @@
   HBasicBlock get start() => expression.start;
   HBasicBlock get end() {
     // We don't create a switch block if there are no cases.
     assert(!statements.isEmpty());
     return statements.last().end;
   }
 
   bool accept(HStatementInformationVisitor visitor) =>
       visitor.visitSwitchInfo(this);
 }