VM: Replace StoreVMField with StoreInstanceField.

runtime/vm/intermediate_language.cc

 // Copyright (c) 2013, 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.
 
 #include "vm/intermediate_language.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/bit_vector.h"
 #include "vm/cpu.h"
 #include "vm/dart_entry.h"
@@ skipping 153 matching lines @@
         return kUnboxedFloat32x4;
       default:
         UNREACHABLE();
     }
   }
   return kTagged;
 }
 
 
 bool StoreInstanceFieldInstr::IsUnboxedStore() const {
-  return FLAG_unbox_numeric_fields && field().IsUnboxedField();
+  return FLAG_unbox_numeric_fields
+      && !field().IsNull()
+      && field().IsUnboxedField();
 }
 
 
 bool StoreInstanceFieldInstr::IsPotentialUnboxedStore() const {
-  return FLAG_unbox_numeric_fields && field().IsPotentialUnboxedField();
+  return FLAG_unbox_numeric_fields
+      && !field().IsNull()
+      && field().IsPotentialUnboxedField();
 }
 
 
 Representation StoreInstanceFieldInstr::RequiredInputRepresentation(
   intptr_t index) const {
   ASSERT((index == 0) || (index == 1));
   if ((index == 1) && IsUnboxedStore()) {
     const intptr_t cid = field().UnboxedFieldCid();
     switch (cid) {
       case kDoubleCid:
@@ skipping 3034 matching lines @@
     case Token::kTRUNCDIV: return 0;
     case Token::kMOD: return 1;
     default: UNIMPLEMENTED(); return -1;
   }
 }
 
 
 #undef __
 
 }  // namespace dart