Make so that array length property access uses a new IC that tracks the array map.

src/stub-cache.h

Index: src/stub-cache.h
diff --git a/src/stub-cache.h b/src/stub-cache.h
index 005c537ab1ed108a5cfccebf491147183b1a5231..dd226b948a8023ba244e361496b0e783a8d1ab0c 100644
--- a/src/stub-cache.h
+++ b/src/stub-cache.h
@@ -90,6 +90,10 @@ class StubCache {
                                    Handle<JSObject> holder,
                                    Handle<AccessorInfo> callback);
 
+  Handle<Code> ComputeLoadArrayLength(Handle<String> name,
+                                      Handle<JSObject> receiver,
+                                      Handle<JSObject> holder);
+
   Handle<Code> ComputeLoadViaGetter(Handle<String> name,
                                     Handle<JSObject> receiver,
                                     Handle<JSObject> holder,
@@ -619,6 +623,12 @@ class LoadStubCompiler: public StubCompiler {
                                    Handle<JSObject> holder,
                                    Handle<AccessorInfo> callback);
 
+  static void GenerateLoadArrayLength(MacroAssembler* masm, Register holder);
+
+  Handle<Code> CompileLoadArrayLength(Handle<String> name,
+                                      Handle<JSObject> receiver,
+                                      Handle<JSObject> holder);
+
   static void GenerateLoadViaGetter(MacroAssembler* masm,
                                     Handle<JSFunction> getter);
 
@@ -643,7 +653,10 @@ class LoadStubCompiler: public StubCompiler {
                                  bool is_dont_delete);
 
  private:
-  Handle<Code> GetCode(Code::StubType type, Handle<String> name);
+  Handle<Code> GetCode(
+      Code::StubType type, Handle<String> name,
+      Code::ExtraICStateForeignCallback callbackType =
+          Code::ExtraICStateForeignCallbackNone);
 };