Host info used to be stored on the global reference underlying a Ref;
now it is stored in a JSWeakMap and hence tied to the lifetime of the
actual object on V8's heap.
Additionally, the internal metadata needed for C-API functions is now
stored on the SharedFunctionInfo and no longer overlaps with the host
info mechanism.

Bonus content:
Roll 6db391e: Remove a few more leftover uses of _enum types

Change-Id: Ibb1fa4b0dd5157fef15c030bac705a11aa3beaea
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1768368Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63400}

This contains the following upstream commits:

486d3fe: Rename DEBUG to WASM_API_DEBUG
8d8e37d: Explicitly number wasm_valkind_t
299ebe0: Fix underlying types for enums
70be7c6: Fix test
Change-Id: I692fb6c909e5211920438740d2c57ea7ee74ab12
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1745483Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63147}

Plus a script to compile/link/run them.

Change-Id: Iac8ffcda3a73902261c07a7b4e5d967a19414c75
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1564058
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60911}