This reverts commit 183bc643.

Reason for revert: https://logs.chromium.org/v/?s=chromium%2Fbb%2Fclient.v8%2FV8_Linux_-_debug%2F18780%2F%2B%2Frecipes%2Fsteps%2FCheck_-_extra%2F0%2Flogs%2Fmemory-size%2F0

Original change's description:
> [wasm] Fix page size constant + test limits on max pages.
> 
> BUG=chromium:801604
> R=​bbudge@chromium.org,titzer@chromium.org
> 
> Change-Id: I5fa57d5f8ea288d7aef7d466cbf11df46c4dcd1d
> Reviewed-on: https://chromium-review.googlesource.com/869468
> Reviewed-by: Ben Titzer <titzer@chromium.org>
> Reviewed-by: Bill Budge <bbudge@chromium.org>
> Commit-Queue: Brad Nelson <bradnelson@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#50665}

TBR=bradnelson@chromium.org,bbudge@chromium.org,titzer@chromium.org

Change-Id: I2b5a51f1a94e862f8ac4455d466e23d26c220202
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:801604
Reviewed-on: https://chromium-review.googlesource.com/872950Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Benedikt Meurer <bmeurer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50666}