Exclude more things from toybox
diff --git a/include/lex.h b/include/lex.h
index 39fca97..bac9024 100644
--- a/include/lex.h
+++ b/include/lex.h
@@ -138,9 +138,11 @@
 
 } BcLexType;
 
+// ** Exclude start. **
 struct BcLex;
 
 typedef BcStatus (*BcLexNext)(struct BcLex*);
+// ** Exclude end. **
 
 typedef struct BcLex {