Mark maps having a hidden prototype rather than maps of hidden prototypes.

src/debug/debug-evaluate.cc

Index: src/debug/debug-evaluate.cc
diff --git a/src/debug/debug-evaluate.cc b/src/debug/debug-evaluate.cc
index e19b93eebea0174e85ae44adb4e2c011589b6405..c76112baffa0a491cbba67c1ccc556d5ef8e2cfe 100644
--- a/src/debug/debug-evaluate.cc
+++ b/src/debug/debug-evaluate.cc
@@ -111,7 +111,7 @@ MaybeHandle<Object> DebugEvaluate::Evaluate(
   // Skip the global proxy as it has no properties and always delegates to the
   // real global object.
   if (result->IsJSGlobalProxy()) {
-    PrototypeIterator iter(isolate, result);
+    PrototypeIterator iter(isolate, Handle<JSGlobalProxy>::cast(result));
     // TODO(verwaest): This will crash when the global proxy is detached.
     result = PrototypeIterator::GetCurrent<JSObject>(iter);
   }