The arm/arm64 simulators debugger has a command "mem" that prints
the content of the memory. It also prints a short summary for JS
objects (SMI, Array, JSFunction, ...). That is very handy, but
when trying to print incomplete initialized memory, it could raise
an exception.

It is useful to have a command that prints the content of the memory
for non-initialized or bogus values without the risk of raising
an exception. This CL adds the command "dump".

Change-Id: I682f97afa30a8d9dc572fe5e9dd256eeebf79de9
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2056468Reviewed-by: Victor Gomes <victorgomes@chromium.org>
Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Auto-Submit: Victor Gomes <victorgomes@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66284}