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/utime.h b/libc/kernel/uapi/linux/utime.h
index 4cc0617..2e98a3d 100644
--- a/libc/kernel/uapi/linux/utime.h
+++ b/libc/kernel/uapi/linux/utime.h
@@ -21,8 +21,8 @@
 #include <linux/types.h>
 struct utimbuf {
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
- __kernel_time_t actime;
- __kernel_time_t modtime;
+  __kernel_time_t actime;
+  __kernel_time_t modtime;
 };
 #endif
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */