"--print-scopes" uses the {function_} variable to print the function
name and locals of a function scope. In case of a pre-parsed function,
the function variable of the scope lives in a zone which is nuked after
pre-parsing, while the scope lives on. This leaves the {function_}
variable pointer in the scope in a state where it points to
invalid memory, causing "--print-scopes" to crash.
This CL fixes the crash by properly resetting the {function_}
pointer.

TBR=verwaest@chromium.org

Change-Id: Id24dbb605bec883317f676265a920fe0ca662301
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1776094Reviewed-by: Simon Zünd <szuend@chromium.org>
Commit-Queue: Simon Zünd <szuend@chromium.org>
Auto-Submit: Simon Zünd <szuend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#63513}