There was a legacy place in map code that wasn't fully ported to use
the strong, new SloppyArgumentsElements type because of code that used
hard-coded constants.

Bug: chromium:1086470
Change-Id: Ieba152e4bd92c89125f831949c2efb4f4219f95c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2215059Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Daniel Clifford <danno@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67984}