Handlify upper layers of StoreIC based on 8337008.

src/ic.h

Index: src/ic.h
diff --git a/src/ic.h b/src/ic.h
index 115405ef3555b4005f2cffe9b7046c3ec8a92e7b..fc302f88753a38dcfc41865e62c092f4446d9988 100644
--- a/src/ic.h
+++ b/src/ic.h
@@ -532,13 +532,11 @@ class StoreIC: public IC {
     return Isolate::Current()->builtins()->builtin(
         Builtins::kStoreIC_Initialize_Strict);
   }
-  Code* global_proxy_stub() {
-    return isolate()->builtins()->builtin(
-        Builtins::kStoreIC_GlobalProxy);
+  Handle<Code> global_proxy_stub() {
+    return isolate()->builtins()->StoreIC_GlobalProxy();
   }
-  Code* global_proxy_stub_strict() {
-    return isolate()->builtins()->builtin(
-        Builtins::kStoreIC_GlobalProxy_Strict);
+  Handle<Code> global_proxy_stub_strict() {
+    return isolate()->builtins()->StoreIC_GlobalProxy_Strict();
   }
 
   static void Clear(Address address, Code* target);