perf tools: Factorize high level dso helpers

Factorize multiple definitions of high level dso helpers into the
symbol source file.

The side effect is a general export of the verbose and eprintf
debugging helpers into a new file dedicated to debugging purposes.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Brice Goglin <Brice.Goglin@inria.fr>

tools/perf/builtin-stat.c

@@ -63,7 +63,6 @@ static struct perf_counter_attr default_attrs[] = {
 #define MAX_RUN			100
 
 static int			system_wide			=  0;
-static int			verbose				=  0;
 static unsigned int		nr_cpus				=  0;
 static int			run_idx				=  0;