Collapse rules that contain only a single token

src/compiler/rules/rule.cpp

@@ -6,6 +6,10 @@ using std::string;
 
 namespace tree_sitter {
     namespace rules {
+        bool Rule::operator!=(const Rule &other) const {
+            return !this->operator==(other);
+        }
+        
         ostream& operator<<(ostream& stream, const Rule &rule) {
             return stream << rule.to_string();
         }