Fixes -Wshadow warnings for ELEMENT.

Bug: v8:12244,v8:12245
Change-Id: Ic3dfa96b44fc18f0db10752639a54aeca324667c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3276928Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Nico Hartmann <nicohartmann@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77954}