This new spec test version is https://github.com/WebAssembly/spec/pull/922 now.

R=titzer@chromium.org

Change-Id: I4e88e6fb5d20e0ab1d4c1011db88171937c0ff86
Reviewed-on: https://chromium-review.googlesource.com/c/1352300Reviewed-by: Ben Titzer <titzer@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57900}