In a benchmark that I'm looking at, the numbers quickly overflow our
current limit.

This patch increases kMaxLength to the greatest value that's possible
without requiring further code changes.

Bug: v8:6791
Change-Id: I7a0d126dcd566d536375a294fa4dcf10b8823ed7
Reviewed-on: https://chromium-review.googlesource.com/833876
Commit-Queue: Georg Neis <neis@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50240}