cppgc: young-gen: Remove DCHECK in RememberedSet::AddWeakCallback

The CL gets rid of the assumption that WeakCallbackItem::parameter
always points to an object with a custom callback, which might not be
the case for weak containers. This fixes failures in cppgc-non-default
bot.

Bug: chromium:1029379
Change-Id: I9ab6cb357153801efaa0d902c9eedff07d12ffe7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3490932Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Anton Bikineev <bikineev@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79296}

src/heap/cppgc/remembered-set.cc

@@ -83,9 +83,9 @@ void OldToNewRememberedSet::AddSourceObject(HeapObjectHeader& hoh) {
 }
 
 void OldToNewRememberedSet::AddWeakCallback(WeakCallbackItem item) {
-  DCHECK(!BasePage::FromInnerAddress(&heap_, item.parameter)
-              ->ObjectHeaderFromInnerAddress(item.parameter)
-              .IsYoung());
+  // TODO(1029379): WeakCallbacks are also executed for weak collections.
+  // Consider splitting weak-callbacks in custom weak callbacks and ones for
+  // collections.
   remembered_weak_callbacks_.insert(item);
 }