In the final version of our pointer compression scheme, decompression
uses zero-extension of the compressed value. The API copy of that code
erroneously still used a sign-extending decompression from an earlier
iteration of the scheme.

Bug: v8:9706, v8:10198
Change-Id: I17c3a52d26ce26bc0623627d725f686c379fbd6e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2051954
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Igor Sheludko <ishell@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66256}