gn: delete some dead code

tools/gn/operators.cc

Index: tools/gn/operators.cc
diff --git a/tools/gn/operators.cc b/tools/gn/operators.cc
index 78ea31b756af497f967bfd1f5eb57ab6b46fe8bc..17e31a728ab398556f09f89e9b82eee883fc9d13 100644
--- a/tools/gn/operators.cc
+++ b/tools/gn/operators.cc
@@ -491,42 +491,6 @@ Value ExecuteAnd(Scope* scope,
 
 // ----------------------------------------------------------------------------
 
-bool IsUnaryOperator(const Token& token) {
-  return token.type() == Token::BANG;
-}
-
-bool IsBinaryOperator(const Token& token) {
-  return token.type() == Token::EQUAL ||
-         token.type() == Token::PLUS ||
-         token.type() == Token::MINUS ||
-         token.type() == Token::PLUS_EQUALS ||
-         token.type() == Token::MINUS_EQUALS ||
-         token.type() == Token::EQUAL_EQUAL ||
-         token.type() == Token::NOT_EQUAL ||
-         token.type() == Token::LESS_EQUAL ||
-         token.type() == Token::GREATER_EQUAL ||
-         token.type() == Token::LESS_THAN ||
-         token.type() == Token::GREATER_THAN ||
-         token.type() == Token::BOOLEAN_AND ||
-         token.type() == Token::BOOLEAN_OR;
-}
-
-bool IsFunctionCallArgBeginScoper(const Token& token) {
-  return token.type() == Token::LEFT_PAREN;
-}
-
-bool IsFunctionCallArgEndScoper(const Token& token) {
-  return token.type() == Token::RIGHT_PAREN;
-}
-
-bool IsScopeBeginScoper(const Token& token) {
-  return token.type() == Token::LEFT_BRACE;
-}
-
-bool IsScopeEndScoper(const Token& token) {
-  return token.type() == Token::RIGHT_BRACE;
-}
-
 Value ExecuteUnaryOperator(Scope* scope,
                            const UnaryOpNode* op_node,
                            const Value& expr,