This CL also fixes a small bug in the update-wasm-spec-tests.sh script,
as it was not able to handle proposals without additional core spec
tests. It also disables a lot of tests.

R=jkummerow@chromium.org
bug:v8:10556

Change-Id: Ibd885350478de935dc67edb664715cfa64f1d8e1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2210248
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67949}