Preserve Smi representation of non-escaping fields.

src/hydrogen-escape-analysis.h

Index: src/hydrogen-escape-analysis.h
diff --git a/src/hydrogen-escape-analysis.h b/src/hydrogen-escape-analysis.h
index 3e27cc1b48b62d652a2b922c3278bd55b3f2bcaa..64ee1ddc0ba657df57c5424446377172515885cd 100644
--- a/src/hydrogen-escape-analysis.h
+++ b/src/hydrogen-escape-analysis.h
@@ -62,6 +62,8 @@ class HEscapeAnalysisPhase : public HPhase {
 
   HValue* NewMapCheckAndInsert(HCapturedObject* state, HCheckMaps* mapcheck);
 
+  void ReplaceFieldLoadWithValue(HLoadNamedField* load, HValue* load_value);
+
   HCapturedObject* StateAt(HBasicBlock* block) {
     return block_states_.at(block->block_id());
   }