This adds a first simple version of the inspector fuzzer, which is a
stripped-down version of the inspector-test executable. The fuzzer
generates inputs which are compatible with inspector-test.

There are still memory leaks, and the fuzzer will probably run into
timeouts most of the time. Both of this will be addressed in follow-ups.

R=szuend@chromium.org, machenbach@chromium.org

Bug: chromium:1142437
Change-Id: I4d13da460f571d791a3642b0705a1f07b442c11b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2505722
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Reviewed-by: Simon Zünd <szuend@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#70922}