Tests were monolithic, with large loops, and slow on ARM64. Refactor to
small tests so they can be sharded better, reduce page size to 1 to
keep the loops small.

BUG=v8:6532

Change-Id: I712551564d4a70fc12acdf114922feb614aeb271
Reviewed-on: https://chromium-review.googlesource.com/611614Reviewed-by: Ben Smith <binji@chromium.org>
Commit-Queue: Deepti Gandluri <gdeepti@chromium.org>
Cr-Commit-Position: refs/heads/master@{#47353}