perf tools: include __WORDSIZE definition

perf tools: include __WORDSIZE definition

__WORDSIZE is GLibC-specific and is not defined on all systems or glibc
versions (e.g. Android's bionic does not define it).

In file included from util/include/linux/bitmap.h:5:0,
                 from util/header.h:10,
                 from util/session.h:6,
                 from util/build-id.h:4,
                 from util/annotate.c:11:
util/include/linux/bitops.h: In function 'set_bit':
util/include/linux/bitops.h:25:12: error:
'__WORDSIZE' undeclared (first use in this function)
util/include/linux/bitops.h:25:12: note:
each undeclared identifier is reported only once for each function it appears in
util/include/linux/bitops.h:23:51: error:
parameter 'addr' set but not used [-Werror=unused-but-set-parameter]
util/include/linux/bitops.h: In function 'clear_bit':
util/include/linux/bitops.h:30:12: error:
'__WORDSIZE' undeclared (first use in this function)
util/include/linux/bitops.h:28:53: error:
parameter 'addr' set but not used [-Werror=unused-but-set-parameter]
In file included from util/header.h:10:0,
                 from util/session.h:6,
                 from util/build-id.h:4,
                 from util/annotate.c:11:
util/include/linux/bitmap.h: In function 'bitmap_zero':
util/include/linux/bitmap.h:22:6: error:
'__WORDSIZE' undeclared (first use in this function)

Defining __WORDSIZE in perf's headers if it is not already defined.

Suggested-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Suggested-by: Pekka Enberg <penberg@kernel.org>
Signed-off-by: Irina Tirdea <irina.tirdea@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Irina Tirdea <irina.tirdea@intel.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1347315303-29906-4-git-send-email-irina.tirdea@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>