This CL introduces a new operator that loads the feedback vector and
checks against maps at runtime, rather than embedding the map directly
in the generated code.

A follow on CL will use this operator when generating code for named
property access.

Bug: v8:10582, v8:9684
Change-Id: I372a01586d3048427760f0cb27619a59afc3f59e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2241518Reviewed-by: Georg Neis <neis@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Sathya Gunasekaran  <gsathya@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68930}