Use native types for inlined native fields.

sdk/lib/_internal/compiler/implementation/ssa/optimize.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;
 
 abstract class OptimizationPhase {
   String get name;
   void visitGraph(HGraph graph);
 }
@@ skipping 672 matching lines @@
       // Some native fields are views of data that may be changed by operations.
       // E.g. node.firstChild depends on parentNode.removeBefore(n1, n2).
       // TODO(sra): Refine the effect classification so that native effects are
       // distinct from ordinary Dart effects.
       isAssignable = true;
     }
     HFieldGet result = new HFieldGet(
         field, receiver, isAssignable: isAssignable);
 
     if (field.getEnclosingClass().isNative()) {
-      result.instructionType =
-          new HType.subtype(field.computeType(compiler), compiler);
+      result.instructionType = new HType.fromNativeBehavior(
+          native.NativeBehavior.ofFieldLoad(field, compiler),
+          compiler);
     } else {
       HType type = new HType.inferredTypeForElement(field, compiler);
       if (type.isUnknown()) {
         type = backend.optimisticFieldType(field);
         if (type != null) {
           backend.registerFieldTypesOptimization(
               work.element, field, result.instructionType);
         }
       }
       if (type != null) {
@@ skipping 1005 matching lines @@
     HBasicBlock block = user.block;
     block.addAfter(user, interceptor);
     block.rewrite(user, interceptor);
     block.remove(user);
 
     // The interceptor will be removed in the dead code elimination
     // phase. Note that removing it here would not work because of how
     // the [visitBasicBlock] is implemented.
   }
 }