Increase from 2^28 - 16 to 2^30 - 25 for 64-bit platforms.

Bug: v8:6148
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_chromium_rel_ng
Change-Id: I3529d7ed757a7ab49a001af8641cf888db171cdb
Reviewed-on: https://chromium-review.googlesource.com/570047Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#46838}