Realm.navigate hits a UAF when it's called after Realm.detachGlobal, and
that's hit a clusterfuzz test.

Bug: chromium:952749
Change-Id: Icf0f0d0b845bc5a2d1ddd80ab52756dae97b982f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1567583Reviewed-by: Benedikt Meurer <bmeurer@chromium.org>
Commit-Queue: Taiju Tsuiki <tzik@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60896}