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/keychord.h b/libc/kernel/uapi/linux/keychord.h
index d13262b..5fd3912 100644
--- a/libc/kernel/uapi/linux/keychord.h
+++ b/libc/kernel/uapi/linux/keychord.h
@@ -22,10 +22,10 @@
 #define KEYCHORD_VERSION 1
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 struct input_keychord {
- __u16 version;
- __u16 id;
- __u16 count;
+  __u16 version;
+  __u16 id;
+  __u16 count;
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
- __u16 keycodes[];
+  __u16 keycodes[];
 };
 #endif