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/if_ether.h b/libc/kernel/uapi/linux/if_ether.h
index b52ccd3..bc032cc 100644
--- a/libc/kernel/uapi/linux/if_ether.h
+++ b/libc/kernel/uapi/linux/if_ether.h
@@ -128,9 +128,9 @@
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #define ETH_P_XDSA 0x00F8
 struct ethhdr {
- unsigned char h_dest[ETH_ALEN];
- unsigned char h_source[ETH_ALEN];
+  unsigned char h_dest[ETH_ALEN];
+  unsigned char h_source[ETH_ALEN];
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
- __be16 h_proto;
+  __be16 h_proto;
 } __attribute__((packed));
 #endif