The current JSObject type is too specific as it can also be passed proxy
objects.

BUG=chromium:1003919,v8:6949

Change-Id: I2766868543827fc5ee6f99f3b120c7ffe9cfed39
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1803651
Auto-Submit: Ross McIlroy <rmcilroy@chromium.org>
Commit-Queue: Mythri Alle <mythria@chromium.org>
Reviewed-by: Mythri Alle <mythria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63787}