This fixes a compilation error with Xcode.

Change-Id: Iaab7cab0d3200c5622f306c7ad0926931d5dce47
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1948716Reviewed-by: Peter Marshall <petermarshall@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Michaël Zasso <mic.besace@gmail.com>
Cr-Commit-Position: refs/heads/master@{#65327}