Add test summary after all test suites finish running.
The summary can be one-line or verbose, which is configured
with CONFIG_ZTEST_VERBOSE_SUMMARY. The one-line summary covers
overall suite stats. The verbose summary covers each test
function within the suite besides the one-line summary.
The new ztest output ultimately go through the printk. If
printk go through the logging subsystem, there may be log
messages dropped. And if log_panic is invoked, log messages
can be flushed in a mess. So several explicit log flush
are used when printing summary to ensure no content is lost
and content is in good shape.
Some macros are shared between old and new ztests. Such as
TC_START_PRINT and TC_END_PRINT. The are defined accordingly.
Signed-off-by: Ming Shao <ming.shao@intel.com>
