It's not very cleaned-up, but may be useful for other developers.

    * tools/build-random/manybuilds

It builds with randomconfig. It remove ppsi configuration so
the wrpc-sw makefile uses a proper one, even if PPSI_FORCE_CONFIG
is false.

It leave around some files: configs and build logs for warning/error
builds, and only the config for good ones. You'll find them
by "git status".

It also avoids re-building and already known good configuration.

    * tools/build-random/unique-error

This filters error builds to only report one per type.

    * tools/build-random/unique-warning

Same for warning-only failures
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>