X87: Avoid HeapObject check in HStoreNamedField.

src/x87/lithium-x87.cc

Index: src/x87/lithium-x87.cc
diff --git a/src/x87/lithium-x87.cc b/src/x87/lithium-x87.cc
index 715c93622748f76736c26128c2989e416668af89..9bb649c1ff5a96a61dc0ee39390cec8e01f1e073 100644
--- a/src/x87/lithium-x87.cc
+++ b/src/x87/lithium-x87.cc
@@ -2379,16 +2379,7 @@ LInstruction* LChunkBuilder::DoStoreNamedField(HStoreNamedField* instr) {
   // We need a temporary register for write barrier of the map field.
   LOperand* temp_map = needs_write_barrier_for_map ? TempRegister() : NULL;
 
-  LInstruction* result =
-      new(zone()) LStoreNamedField(obj, val, temp, temp_map);
-  if (!instr->access().IsExternalMemory() &&
-      instr->field_representation().IsHeapObject() &&
-      (val->IsConstantOperand()
-       ? HConstant::cast(instr->value())->HasSmiValue()
-       : !instr->value()->type().IsHeapObject())) {
-    result = AssignEnvironment(result);
-  }
-  return result;
+  return new(zone()) LStoreNamedField(obj, val, temp, temp_map);
 }