Allow monomorphic loads when static type is known.

src/hydrogen-instructions.h

Index: src/hydrogen-instructions.h
diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index 367d2b32fb037369b1ae58db8d41e22c8cee2b66..aa513e707b235c8a20a63a55acacfa78b6189e82 100644
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -770,6 +770,14 @@ class HValue: public ZoneObject {
 
   const char* Mnemonic() const;
 
+  // Type information helpers.
+  bool HasMonomorphicJSObjectType();
+
+  // TODO(mstarzinger): For now instructions can override this function to
+  // specify statically known types, once HType can convey more information
+  // it should be based on the HType.
+  virtual Handle<Map> GetMonomorphicJSObjectMap() { return Handle<Map>(); }
+
   // Updated the inferred type of this instruction and returns true if
   // it has changed.
   bool UpdateInferredType();
@@ -5019,6 +5027,10 @@ class HAllocateObject: public HTemplateInstruction<1> {
   virtual Representation RequiredInputRepresentation(int index) {
     return Representation::Tagged();
   }
+  virtual Handle<Map> GetMonomorphicJSObjectMap() {
+    ASSERT(constructor()->has_initial_map());
+    return Handle<Map>(constructor()->initial_map());
+  }
   virtual HType CalculateInferredType();
 
   DECLARE_CONCRETE_INSTRUCTION(AllocateObject)
@@ -5086,6 +5098,9 @@ class HFastLiteral: public HMaterializedLiteral<1> {
   virtual Representation RequiredInputRepresentation(int index) {
     return Representation::Tagged();
   }
+  virtual Handle<Map> GetMonomorphicJSObjectMap() {
+    return Handle<Map>(boilerplate()->map());
+  }
   virtual HType CalculateInferredType();
 
   DECLARE_CONCRETE_INSTRUCTION(FastLiteral)