Overview:
- Change basic type hierarchy to split Tagged into StrongTagged (= Object) and
and WeakHeapObject. This enables to emit the right CSA types (Object, MaybeObject).
- The new Weak<T> type encodes a possibly cleared weak bit pattern that
points to type T if it's not cleared.
- Make TNode<Object> a subtype of TNode<MaybeObject> so that the generated code
compiles on the C++ side. Drive-by change: simplify a few CSA helpers by using
MaybeObject as a common supertype of MaybeObject and Object.
- Port CreateObjectWithoutProperties and LoadMapPrototypeInfo.
Bug: v8:7793
Change-Id: I895a6501ce3e287ea8cf4065aaff3a5535245ab4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1889870
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Commit-Queue: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64876}
1b04772f7f