This is a reland of fd49c8bb

Original change's description:
> [heap] Optimize MemoryChunk::FromAnyPointerAddress
> 
> Currently this function requires the caller to hold a mutex for the
> large page chunk hashtable and performs a hashtable lookup.
> 
> This patch adds a header sentinel field in each MemoryChunk. The field
> is then used to distinguish large object slots from ordinary slots.
> 
> Bug: chromium:915233
> Change-Id: I9fbeeb4f07f49573d0a21f9a2cc934370e417d68
> Reviewed-on: https://chromium-review.googlesource.com/c/1391752
> Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
> Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#58732}

Bug: chromium:915233
Change-Id: I10d23a928328169a2dc6bab78d2b7d2c5d00ebb6
Reviewed-on: https://chromium-review.googlesource.com/c/1406672
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58876}