This CL fixes a bug where function proxies were reported as functions
instead as proxies to devtools, which caused dev-tools to call methods
on the function, possibly triggering side-effects.

Change-Id: I1d5d234b784601bd4b7ec91107e4b0cf0d877d07
Bug: chromium:995753
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1762303Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Sigurd Schneider <sigurds@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63307}