I2S:
https://groups.google.com/a/chromium.org/g/blink-dev/c/r6yl8pfmf9s/m/ApOmYIuNBgAJ

Also adds findLast and findLastIndex to the list of no-side-effect
builtins for the debugger.

Bug: v8:11990
Change-Id: I285bf499afc2632ffb4e22cf2ea13c978e21e979
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3217757Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Shu-yu Guo <syg@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77328}