Also add tests for it.

Drive-by fix: Use ChangeInt32ToCompressedSmi since we have it

Cq-Include-Trybots: luci.v8.try:v8_linux64_pointer_compression_rel_ng
Cq-Include-Trybots: luci.v8.try:v8_linux64_arm64_pointer_compression_rel_ng
Bug: v8:7703
Change-Id: I45f04f8857acfc57b69eb4022a24ba082d28a91f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1708480Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62871}