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/hpet.h b/libc/kernel/uapi/linux/hpet.h
index 1925428..98bf725 100644
--- a/libc/kernel/uapi/linux/hpet.h
+++ b/libc/kernel/uapi/linux/hpet.h
@@ -21,10 +21,10 @@
 #include <linux/compiler.h>
 struct hpet_info {
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
- unsigned long hi_ireqfreq;
- unsigned long hi_flags;
- unsigned short hi_hpet;
- unsigned short hi_timer;
+  unsigned long hi_ireqfreq;
+  unsigned long hi_flags;
+  unsigned short hi_hpet;
+  unsigned short hi_timer;
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 };
 #define HPET_INFO_PERIODIC 0x0010