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/mpls.h b/libc/kernel/uapi/linux/mpls.h
index e84d8e7..64b4279 100644
--- a/libc/kernel/uapi/linux/mpls.h
+++ b/libc/kernel/uapi/linux/mpls.h
@@ -22,7 +22,7 @@
 #include <asm/byteorder.h>
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 struct mpls_label {
- __be32 entry;
+  __be32 entry;
 };
 #define MPLS_LS_LABEL_MASK 0xFFFFF000
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */