Address a few TODOs related to type propagation.

runtime/vm/intermediate_language.h

 // 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.
 
 #ifndef VM_INTERMEDIATE_LANGUAGE_H_
 #define VM_INTERMEDIATE_LANGUAGE_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
@@ skipping 934 matching lines @@
  private:
   const intptr_t offset_in_bytes_;
   const AbstractType& type_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeLoadFieldComp);
 };
 
 
 class NativeStoreFieldComp : public TemplateComputation<2> {
  public:
-  NativeStoreFieldComp(Value* dest, intptr_t offset_in_bytes, Value* value)
-      : offset_in_bytes_(offset_in_bytes) {
+  NativeStoreFieldComp(Value* dest,
+                       intptr_t offset_in_bytes,
+                       Value* value,
+                       const AbstractType& type)
+      : offset_in_bytes_(offset_in_bytes), type_(type) {
     ASSERT(value != NULL);
+    ASSERT(type.IsZoneHandle());  // May be null if field is not an instance.
     inputs_[0] = dest;
     inputs_[1] = value;
   }
 
   DECLARE_COMPUTATION(NativeStoreField)
 
   Value* dest() const { return inputs_[0]; }
   Value* value() const { return inputs_[1]; }
   intptr_t offset_in_bytes() const { return offset_in_bytes_; }
+  const AbstractType& type() const { return type_; }
 
  private:
   const intptr_t offset_in_bytes_;
+  const AbstractType& type_;
 
   DISALLOW_COPY_AND_ASSIGN(NativeStoreFieldComp);
 };
 
 
 class InstantiateTypeArgumentsComp : public TemplateComputation<1> {
  public:
   InstantiateTypeArgumentsComp(intptr_t token_index,
                                intptr_t try_index,
                                const AbstractTypeArguments& type_arguments,
@@ skipping 707 matching lines @@
   const GrowableArray<BlockEntryInstr*>& block_order_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(FlowGraphVisitor);
 };
 
 
 }  // namespace dart
 
 #endif  // VM_INTERMEDIATE_LANGUAGE_H_