The {DiscardSystemPages} call occasionally fails on win32, thus disable
it until the error is found.

R=mstarzinger@chromium.org

Bug: v8:8217, chromium:960707
Change-Id: Idf77dd8e85d3d38cc12a9f4d2db5cc98eb2c7d08
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1601150Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61331}