Newer gcc introduces newer & richer debuginfo, and only libdw
in elfutils project can support it. So perf probe moves onto
elfutils-libdw from libdwarf.

Changes in v3:
 - Cast Dwarf_Addr/Dwarf_Word to uintmax_t for printf-formats.
 - Recover a sign-prefix which was removed in v2 by mistake.

Changes in v2:
 - Fix a type-casting bug in Makefile.
 - Cast Dwarf_Addr/Dwarf_Word to unsigned long long for printf-formats.

Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com>
Cc: systemtap <systemtap@sources.redhat.com>
Cc: DLE <dle-develop@lists.sourceforge.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: K.Prasad <prasad@linux.vnet.ibm.com>
Cc: Ulrich Drepper <drepper@redhat.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
LKML-Reference: <20100225133542.6725.34724.stgit@localhost6.localdomain6>
Signed-off-by: Ingo Molnar <mingo@elte.hu>