Adds support to webassembly and enables it by default.
Adds wee8 target.

We can compile without wasm with:
`bazel build :d8 --no//:v8_enable_webassembly`

Bug: v8:11234
Change-Id: I90b11eb71aed808005b66e40e37894616d8b1658
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2960803
Commit-Queue: Victor Gomes <victorgomes@chromium.org>
Reviewed-by: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75200}

Command to build: `bazel build :d8`

Caveats:
  - Needs clang
  - Only supports x64 on Linux
  - Bare V8: no Wasm and no ICU
  - Still needs GN to generate inspector files

Bug: v8:11234
Change-Id: I6d01fecff5fba5c3582995d071692e5c6c6c6310
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2960949
Commit-Queue: Victor Gomes <victorgomes@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75155}