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/nfsd/export.h b/libc/kernel/uapi/linux/nfsd/export.h
index 216bb23..4d7bfad 100644
--- a/libc/kernel/uapi/linux/nfsd/export.h
+++ b/libc/kernel/uapi/linux/nfsd/export.h
@@ -43,6 +43,6 @@
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define NFSEXP_V4ROOT 0x10000
 #define NFSEXP_ALLFLAGS 0x1FE7F
-#define NFSEXP_SECINFO_FLAGS (NFSEXP_READONLY | NFSEXP_ROOTSQUASH   | NFSEXP_ALLSQUASH   | NFSEXP_INSECURE_PORT)
+#define NFSEXP_SECINFO_FLAGS (NFSEXP_READONLY | NFSEXP_ROOTSQUASH | NFSEXP_ALLSQUASH | NFSEXP_INSECURE_PORT)
 #endif
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */