Update kernel headers to v3.14.

Other changes:
- Modify update_all.py to skip ion header files when importing into aosp.
- Fix generate_uapi_headers.sh to handle imports from a linux-stable kernel.

Change-Id: I1ad81b9ccb063c21740f9875f2cc1238052cd4b3
diff --git a/libc/kernel/uapi/linux/const.h b/libc/kernel/uapi/linux/const.h
index d348300..9a85be7 100644
--- a/libc/kernel/uapi/linux/const.h
+++ b/libc/kernel/uapi/linux/const.h
@@ -28,4 +28,7 @@
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define _AT(T,X) ((T)(X))
 #endif
+#define _BITUL(x) (_AC(1,UL) << (x))
+#define _BITULL(x) (_AC(1,ULL) << (x))
+/* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #endif