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

src/stub-cache.cc

Index: src/stub-cache.cc
diff --git a/src/stub-cache.cc b/src/stub-cache.cc
index 5eb0cbaa1cb7158b182a241130de7081a082fd51..75f56b4580cba8811ff9d0adac150d93ed062775 100644
--- a/src/stub-cache.cc
+++ b/src/stub-cache.cc
@@ -173,6 +173,27 @@ Handle<Code> StubCache::ComputeLoadCallback(Handle<String> name,
 }
 
 
+Handle<Code> StubCache::ComputeLoadArrayLength(Handle<String> name,
+                                               Handle<JSObject> receiver,
+                                               Handle<JSObject> holder) {
+  ASSERT(IC::GetCodeCacheForObject(*receiver, *holder) == OWN_MAP);
+  Code::Flags flags =
+      Code::ComputeMonomorphicFlags(
+          Code::LOAD_IC, Code::CALLBACKS,
+          Code::ExtraICStateForeignCallbackArrayLength);
+  Handle<Object> probe(receiver->map()->FindInCodeCache(*name, flags));
+  if (probe->IsCode()) return Handle<Code>::cast(probe);
+
+  LoadStubCompiler compiler(isolate_);
+  Handle<Code> code =
+      compiler.CompileLoadArrayLength(name, receiver, holder);
+  PROFILE(isolate_, CodeCreateEvent(Logger::LOAD_IC_TAG, *code, *name));
+  GDBJIT(AddCode(GDBJITInterface::LOAD_IC, *name, *code));
+  JSObject::UpdateMapCodeCache(receiver, name, code);
+  return code;
+}
+
+
 Handle<Code> StubCache::ComputeLoadViaGetter(Handle<String> name,
                                              Handle<JSObject> receiver,
                                              Handle<JSObject> holder,
@@ -1373,9 +1394,12 @@ void StubCompiler::LookupPostInterceptor(Handle<JSObject> holder,
 }
 
 
-Handle<Code> LoadStubCompiler::GetCode(Code::StubType type,
-                                       Handle<String> name) {
-  Code::Flags flags = Code::ComputeMonomorphicFlags(Code::LOAD_IC, type);
+Handle<Code> LoadStubCompiler::GetCode(
+    Code::StubType type,
+    Handle<String> name,
+    Code::ExtraICStateForeignCallback callbackType) {
+  Code::Flags flags = Code::ComputeMonomorphicFlags(
+      Code::LOAD_IC, type, Code::ExtraICState(callbackType));
   Handle<Code> code = GetCodeWithFlags(flags, name);
   PROFILE(isolate(), CodeCreateEvent(Logger::LOAD_IC_TAG, *code, *name));
   GDBJIT(AddCode(GDBJITInterface::LOAD_IC, *name, *code));