Now that we can represent specific weak types with Weak<T>, this CL
updates the generated verifier functions so that they permit weak
references only to the specified type. As an example, consider the
verifier emitted for the following field in PrototypeInfo:

  object_create_map: Weak<Map>|Undefined;

We used to emit the following, which allowed any weak reference:

  CHECK(object_create_map__value.IsWeakOrCleared()
      || object_create_map__value.GetHeapObjectOrSmi().IsOddball());

With this change, we emit a stricter check:

  CHECK(object_create_map__value.IsCleared()
      || (!object_create_map__value.IsWeak()
          && object_create_map__value.GetHeapObjectOrSmi().IsOddball())
      || (object_create_map__value.IsWeak()
          && object_create_map__value.GetHeapObjectOrSmi().IsMap()));

Bug: v8:7793
Change-Id: I4be236d97dedbcdd6c98207928aee8bda2a77f00
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1914613
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64965}