Addds a crash-time helper to dump a MultiSink used for proto encoded
logs.
Change-Id: I5b8efb3f2d3c86f403896fca9cdd4ddde5e6cc39
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/63282
Pigweed-Auto-Submit: Armando Montanez <amontanez@google.com>
Commit-Queue: Armando Montanez <amontanez@google.com>
Reviewed-by: Ewout van Bekkum <ewout@google.com>