We add final types to wasm-gc.
- We introduce a `kWasmSubtypeFinalCode` as an alternative to
`kWasmSubtypeCode`.
- Behind a flag, we interpret types behind this code as final, as well
as types outside a subtype definition by default.
- For final types, type checks for call_indirect and ref.test etc. are
reduced to simple type identity checks.
Bug: v8:7748
Change-Id: Iabf147b2a15f43abc4c7d1c582f460dbdc645d66
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/4096478
Reviewed-by: Matthias Liedtke <mliedtke@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Cr-Commit-Position: refs/heads/main@{#84955}
2f852102d9