tracing/selftests: Update synthetic event selftest to use common_stacktrace

With the rename of the stacktrace field to common_stacktrace, update the
selftests to reflect this change. Copy the current selftest to test the
backward compatibility "stacktrace" keyword. Also the "requires" of that
test was incorrect, so it would never actually ran before. That is fixed
now.

Link: https://lore.kernel.org/linux-trace-kernel/20230523225402.55951f2f@rorschach.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

tracing/histogram: Add simple tests for stacktrace usage of synthetic events

Update the selftests to include a test of passing a stacktrace between the
events of a synthetic event.

Link: https://lkml.kernel.org/r/20230117152236.475439286@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Ching-lin Yu <chinglinyu@google.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>