Fix missing include

tests/test_BuiltinFunctionRegister.hpp

@@ -7,6 +7,8 @@
 #include <language/utils/TypeDescriptor.hpp>
 #include <utils/Exceptions.hpp>
 
+#include <unordered_map>
+
 template <>
 inline ASTNodeDataType ast_node_data_type_from<std::shared_ptr<const double>> =
   ASTNodeDataType::build<ASTNodeDataType::type_id_t>("builtin_t");