This reverts commit 20327d1599.
Reason for revert: The code for structref/dataref is in use in
combination with array types, so the change breaks their use cases.
Reverting to restore the previous semantics of dataref.
Original change's description:
> [wasm-gc] Ref types: Convert dataref to structref
>
> This change changes the type hierarchy in a non-backwards compatible
> way: dataref is replaced with structref meaning that arrayref is
> no longer a subtype of it.
>
> Bug: v8:7748
> Change-Id: I965267d9ed11ea7c7d7df133cc39ee63e6b5abc3
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3929041
> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
> Commit-Queue: Matthias Liedtke <mliedtke@chromium.org>
> Cr-Commit-Position: refs/heads/main@{#83515}
Bug: v8:7748
Change-Id: I2a0bcafafe6f67df87aac86813f74573b708cce4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3936156
Commit-Queue: Matthias Liedtke <mliedtke@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#83544}