WasmValue holds a Wasm value with its type. This will be exposed to the
inspector (via a to-be-created class in debug_interface.h) for debugging
in DevTools.

Design at http://doc/1XQlX6DWsv6BPYnRtw-JZSASPEjsRlyXLnke7TTQ9Wrg.

Bug: v8:10347
Change-Id: Ib523e617d46fdf1adb13d13bf49749c4ce23a126
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2132720Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Kim-Anh Tran <kimanh@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67029}