Refactoring ScopeInfo::ContextSlotIndex so it accepts a pointer to
LookupResult instead of references to the individual arguments.

Change-Id: I52bc7800f14e790bd4788c213ab0eff2354ab20e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2900837
Commit-Queue: Luis Fernando Pardo Sixtos <lpardosixtos@microsoft.com>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74683}