user_events: Add self-test for perf_event integration

Tests perf can be attached to and written out correctly. Ensures attach
updates status bits in user programs.

Link: https://lkml.kernel.org/r/20220118204326.2169-10-beaub@linux.microsoft.com



Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>