This is follow-up of 289d25c1
Improve loop using Subslice, improve common-case check.

Bug: v8:8996
Change-Id: I59ba14b87e1b034fd2d41c92a506e142550363ce
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2527608
Commit-Queue: Z Nguyen-Huu <duongn@microsoft.com>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#71666}