Port 9d3c9d47

Original Commit Message:

    So far the slot is set to 0; in an upcoming CL it will be
    used for an actual feedback vector.

R=jkummerow@chromium.org, joransiu@ca.ibm.com, junyan@redhat.com, midawson@redhat.com
BUG=
LOG=N

Change-Id: Idbaa1d11fbfe81cf1106e4796c82ae6a1d6c1a11
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3212330Reviewed-by: Junliang Yan <junyan@redhat.com>
Commit-Queue: Milad Fa <mfarazma@redhat.com>
Cr-Commit-Position: refs/heads/main@{#77289}