Load the native call wrapper via Thread.

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index e5b501fc77398f4b51d0da016fc01d613dcff060..2366142b7a56dacf9e74fbdcb5ace7e723b849d9 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -11036,7 +11036,6 @@ void ObjectPool::PrintJSONImpl(JSONStream* stream, bool ref) const {
         imm = RawValueAt(i);
         jsarr.AddValue64(imm);
         break;
-      case ObjectPool::kExternalLabel:
       case ObjectPool::kNativeEntry:
         imm = RawValueAt(i);
         jsarr.AddValueF("0x%" Px, imm);
@@ -11049,16 +11048,6 @@ void ObjectPool::PrintJSONImpl(JSONStream* stream, bool ref) const {
 }
 
 
-static const char* DescribeExternalLabel(uword addr) {
-  const char* stub_name = StubCode::NameOfStub(addr);
-  if (stub_name != NULL) {
-    return stub_name;
-  }
-
-  return "UNKNOWN";
-}
-
-
 void ObjectPool::DebugPrint() const {
   THR_Print("Object Pool: {\n");
   for (intptr_t i = 0; i < Length(); i++) {
@@ -11069,10 +11058,6 @@ void ObjectPool::DebugPrint() const {
       THR_Print("0x%" Px " %s (obj)\n",
           reinterpret_cast<uword>(obj),
           Object::Handle(obj).ToCString());
-    } else if (InfoAt(i) == kExternalLabel) {
-      uword addr = RawValueAt(i);
-      THR_Print("0x%" Px " (external label: %s)\n",
-                addr, DescribeExternalLabel(addr));
     } else if (InfoAt(i) == kNativeEntry) {
       THR_Print("0x%" Px " (native entry)\n", RawValueAt(i));
     } else {