x86_64 ia32 ptrace: convert to compat_arch_ptrace

Now that there are no more special cases in sys32_ptrace, we
can convert to using the generic compat_sys_ptrace entry point.
The sys32_ptrace function gets simpler and becomes compat_arch_ptrace.

Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/include/asm-x86/ptrace.h b/include/asm-x86/ptrace.h
index 24ec061..9f922b0 100644
--- a/include/asm-x86/ptrace.h
+++ b/include/asm-x86/ptrace.h
@@ -231,6 +231,8 @@
 extern int do_set_thread_area(struct task_struct *p, int idx,
 			      struct user_desc __user *info, int can_allocate);
 
+#define __ARCH_WANT_COMPAT_SYS_PTRACE
+
 #endif /* __KERNEL__ */
 
 #endif /* !__ASSEMBLY__ */