Some output is written, some is not
Finally concluded it's a Perl bug: after running with parallel threads
  for a while, print suddenly ignores all but the first argument.
Workaround: concatenate all the arguments into one, except in output that
  only comes before we start running tests

Prepend "Completed", "Timeout" or "Too many failed" to summary line

There's no need for --verbose for the mysqltest in check-warnings, remove it

instead of making it experimental.

Remove the extra line which try to use the name INNOBASE again. The IF ELSE
loop above declares the library name based on the version of mysql

push_warning(MYSQL_ERROR::WARN_LEVEL_ERROR)).

The Signal/Resignal patch changes the push_warning() API: now
it silently downgrades WARN_LEVEL_ERROR to WARN_LEVEL_WARN.

This patch should be rolled back when Bug#47233 is fixed.

Knowledge of no SSL support is not used
Skip tests the same way e.g. innodb tests are
Does not refer to have_ssl_communication.inc, 
     will add this when merging to 6.0-codebase

Don't print entire log, but use extract_server_log() introduced by 46007