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/atmclip.h b/libc/kernel/uapi/linux/atmclip.h
index 346e402..a266b83 100644
--- a/libc/kernel/uapi/linux/atmclip.h
+++ b/libc/kernel/uapi/linux/atmclip.h
@@ -26,5 +26,5 @@
 #define CLIP_DEFAULT_IDLETIMER 1200
 #define CLIP_CHECK_INTERVAL 10
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
-#define SIOCMKCLIP _IO('a',ATMIOC_CLIP)
+#define SIOCMKCLIP _IO('a', ATMIOC_CLIP)
 #endif