Implement coverage tracking for optional chains.

Bug: v8:10060
Change-Id: I4f29eda64b6d859939f5f58f4fabead649905795
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2573013Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Reviewed-by: Gus Caplan <snek@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Benjamin Coe <bencoe@google.com>
Cr-Commit-Position: refs/heads/master@{#72075}