Re-use InstallConstructorFunc and remove an obsolete comment.

R=ahaas@chromium.org

Change-Id: I1143d3e58e968b9210cef5045d8221d20ed18419
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2886859Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74499}