* refs/pull/22586/head:
global/signal_handler: one less frame of context
global/signal_handler: write crash dumps to /var/lib/ceph/crash/$uuid/
common/ceph_context: add "assert" and "abort" asok commands
common/assert: record assert info in g_assert_* globals
common: add crash_dir option
common/assert: get rid of duplicate log dump from assert handler
common/BackTrace: add dump()
log: do not discard recent after dumping it
debian,rpm: /var/lib/ceph/crash
