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/asm-generic/param.h b/libc/kernel/uapi/asm-generic/param.h
index 416c4fb..aa21864 100644
--- a/libc/kernel/uapi/asm-generic/param.h
+++ b/libc/kernel/uapi/asm-generic/param.h
@@ -27,7 +27,7 @@
 #endif
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
 #ifndef NOGROUP
-#define NOGROUP (-1)
+#define NOGROUP (- 1)
 #endif
 #endif
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */