Liftoff increases code size, and people start deploying bigger modules.
Increase the wasm code space limit from 512 MB to 1024 MB to account
for this.

R=titzer@chromium.org

Bug: chromium:883639, chromium:872684
Change-Id: I3a2ca29d456635f7f3aa1daef5fa2b0249dc1645
Reviewed-on: https://chromium-review.googlesource.com/1226971
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Ben Titzer <titzer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56003}