perf annotate browser: Allow navigation to called functions

perf annotate browser: Allow navigation to called functions

I.e. when in the annotate TUI window, if Enter is pressed over an
assembly line with a 'callq' it will try to open another TUI window with
that symbol.

This is just a proof of concept and works only on x86_64, more work is
needed to support kernel modules, userland, other arches, etc, but
should already be useful as-is.

Suggested-by: Ingo Molnar <mingo@elte.hu>
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-opyvskw5na3qdmkv8vxi3zbr@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>