This CL changes the WasmTypeInfo class to have a direct ExternalPointer
to the native type structure instead of using a Foreign. This in turn
makes it possible to use a unique pointer tag for that external pointer
when the sandbox is enabled.

Bug: v8:10391, v8:12949
Change-Id: Ifee4d2103cabfa6a7299d0d09e06d387034e5f8f
Cq-Include-Trybots: luci.v8.try:v8_linux64_heap_sandbox_dbg_ng,v8_linux_arm64_sim_heap_sandbox_dbg_ng
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3829085Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Samuel Groß <saelo@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82504}