Switch kernel header parsing to python libclang

Replace the tokenizer in cpp.py with libclang.

Bug: 18937958
Change-Id: I27630904c6d2849418cd5ca3d3c612ec3078686d
diff --git a/libc/kernel/uapi/linux/if_tun.h b/libc/kernel/uapi/linux/if_tun.h
index f8f80b9..dd2dc2a 100644
--- a/libc/kernel/uapi/linux/if_tun.h
+++ b/libc/kernel/uapi/linux/if_tun.h
@@ -84,16 +84,16 @@
 #define TUN_F_UFO 0x10
 #define TUN_PKT_STRIP 0x0001
 struct tun_pi {
- __u16 flags;
+  __u16 flags;
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
- __be16 proto;
+  __be16 proto;
 };
 #define TUN_FLT_ALLMULTI 0x0001
 struct tun_filter {
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
- __u16 flags;
- __u16 count;
- __u8 addr[0][ETH_ALEN];
+  __u16 flags;
+  __u16 count;
+  __u8 addr[0][ETH_ALEN];
 };
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #endif