This reverts commit 45ea0150.

Reason for revert: Breaks UBSan - https://ci.chromium.org/p/v8/builders/ci/V8%20Linux64%20UBSan/9777

Original change's description:
> [wasm] Use memcmp to compare module bytes
> 
> This is much faster than std::lexicographical_compare.
> 
> R=​clemensb@chromium.org
> 
> Bug: chromium:1048554
> Change-Id: I5f0ba22654e172535b6e6fcf6d2a460e278d3cfd
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2036078
> Reviewed-by: Clemens Backes <clemensb@chromium.org>
> Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#66109}

TBR=clemensb@chromium.org,thibaudm@chromium.org

Change-Id: Ic4323af356bfd2698043b4f3ecb21367f1044446
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: chromium:1048554
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2037430Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66111}