Some Linux symbols (for example __vt_event_wait) are interpreted by the
demangler as C++ mangled names, which of course they aren't.

Disable kernel symbol demangling by default to avoid this, and allow
enabling it with a new option --demangle-kernel for those who wish it.
Reported-by: NJiri Olsa <jolsa@redhat.com>
Signed-off-by: NAvi Kivity <avi@cloudius-systems.com>
Acked-by: NJiri Olsa <jolsa@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1410581705-26968-1-git-send-email-avi@cloudius-systems.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>