perf test: Allow running just a subset of the available tests

perf test: Allow running just a subset of the available tests

To obtain a list of available tests:

[root@emilia linux]# perf test list
 1: vmlinux symtab matches kallsyms
 2: detect open syscall event
 3: detect open syscall event on all cpus
 4: read samples using the mmap interface
 5: parse events tests
[root@emilia linux]#

To list just a subset:

[root@emilia linux]# perf test list syscall
 2: detect open syscall event
 3: detect open syscall event on all cpus
[root@emilia linux]#

To run a subset:

[root@emilia linux]# perf test detect
 2: detect open syscall event: Ok
 3: detect open syscall event on all cpus: Ok
[root@emilia linux]#

Specific tests can be chosen by number:

[root@emilia linux]# perf test 1 3 parse
 1: vmlinux symtab matches kallsyms: Ok
 3: detect open syscall event on all cpus: Ok
 5: parse events tests: Ok
[root@emilia linux]#

Now to write more tests!

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-nqec2145qfxdgimux28aw7v8@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>