x86: Move is_ia32_task to asm/thread_info.h from asm/compat.h

is_ia32_task() is useful even in !CONFIG_COMPAT cases - utrace will
use it for example. Hence move it to a more generic file: asm/thread_info.h

Also now is_ia32_task() returns true if CONFIG_X86_32 is defined.

Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Jim Keniston <jkenisto@linux.vnet.ibm.com>
Cc: Linux-mm <linux-mm@kvack.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Arnaldo Carvalho de Melo <acme@infradead.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20120313140303.17134.1401.sendpatchset@srdronam.in.ibm.com


[ Performed minor cleanup ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>