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/un.h b/libc/kernel/uapi/linux/un.h
index 736b5bf..07f615e 100644
--- a/libc/kernel/uapi/linux/un.h
+++ b/libc/kernel/uapi/linux/un.h
@@ -22,8 +22,8 @@
 #define UNIX_PATH_MAX 108
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 struct sockaddr_un {
- __kernel_sa_family_t sun_family;
- char sun_path[UNIX_PATH_MAX];
+  __kernel_sa_family_t sun_family;
+  char sun_path[UNIX_PATH_MAX];
 };
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #endif