x86: Factor out TIF_IA32 from 32-bit address space

Factor out IA32 (compatibility instruction set) from 32-bit address
space in the thread_info flags; this is a precondition patch for x32
support.

Originally-by: H. J. Lu <hjl.tools@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/n/tip-4pr1xnnksprt7t0h3w5fw4rv@git.kernel.org
diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c
index bff89df..d6aa6e8 100644
--- a/arch/x86/oprofile/backtrace.c
+++ b/arch/x86/oprofile/backtrace.c
@@ -67,7 +67,7 @@
 {
 	struct stack_frame_ia32 *head;
 
-	/* User process is 32-bit */
+	/* User process is IA32 */
 	if (!current || !test_thread_flag(TIF_IA32))
 		return 0;