This is a border case that appeared in one of our tests. It seems a good
idea to test for it. It does not seem to be common enough to handle it
specifically (i.e replacing the Word64Equal with a true bool constant)

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: v8:8977, v8:7703
Change-Id: I27e85a2493ab03b92591e788a185d6109904eef1
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1613252Reviewed-by: Jaroslav Sevcik <jarin@chromium.org>
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61726}