This removes an outdated section order check from {CreateNewBuffer} and
relies solely on the checks done in {ProcessSection}. Those checks are
more comprehensive and will remain coherent with synchronous decoding.

R=ahaas@chromium.org
TEST=mjsunit/regress/wasm/regress-8846
BUG=v8:8846

Change-Id: Id0cdc3bf3ad78f7970c9fceff66a17ab20f4666b
Reviewed-on: https://chromium-review.googlesource.com/c/1477211Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59702}