By having the proposal tests now as part of the wasm-spec-tests, we do
not need them here anymore.

R=clemensh@chromium.org
CC=binji@chromium.org

Change-Id: I2530a4d2e2e8caa6fe8ef4d7e7b8b6da550a5134
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1706475Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62778}