At the moment we only run the js-api spec tests of the core API on our
try bots. With the new staging process we want to introduce for
WebAssembly language features, see
https://docs.google.com/document/d/1hB8mpWmzmtaxZ8PuJEkAWLwFqXTjrw7mJ3Ge9W1dB4E,
we also want to run the js-api spec tests of proposals for which we
already staged the implementation. With this CL I do the following
changes:

1) The tools/wasm/update-wasm-spec-tests.sh now copies the js-api spec
   tests of the main spec and of the proposals to test/wasm-js/tests,
   and then uploads this directory to google cloud storage. The main
   spec tests are in test/wasm-js/tests, the proposal tests are in
   test/wasm-js/tests/proposals/PROPOSAL_NAME/.
2) Adjust the test-runner in test/wasm-js to run tests in
   tests/* instead of data/test/js-api/*. Thereby it also runs the
   proposal tests in test/wasm-js/tests/proposals/PROPOSAL_NAME/.
   For the proposal tests, the test runner now also adds d8 flags.
3) Remove the dependency to https://github.com/WebAssembly/spec from
   DEPS.
4) Cleanup .gitignore and wasm-js.status
5) Disable spec tests we don't pass with the new proposal.

R=tmrts@chromium.org

Bug: v8:9653
Change-Id: Ib3420871f17cb146d6cc7868f5613942a7f79d84
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1768372
Commit-Queue: Tamer Tas <tmrts@chromium.org>
Reviewed-by: Tamer Tas <tmrts@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63419}