Add missing tests for ASTNodeBuiltinFunctionExpressionBuilder

Also remove the treatment of tuple of function arguments, since this kind of argument cannot be defined in the language (by now?).

src/language/utils/SymbolTable.hpp

@@ -353,15 +353,8 @@ class SymbolTable
   add(const std::string& symbol_name, const TAO_PEGTL_NAMESPACE::position& symbol_position)
   {
     for (auto i_stored_symbol = m_symbol_list.begin(); i_stored_symbol != m_symbol_list.end(); ++i_stored_symbol) {
-      std::string_view stored_symbol_name = i_stored_symbol->name();
-      if (stored_symbol_name.size() == symbol_name.size()) {
-        if (stored_symbol_name == symbol_name) {
-          return std::make_pair(i_stored_symbol, false);
-        } else if (stored_symbol_name.size() > symbol_name.size() and (stored_symbol_name[symbol_name.size()] == ':')) {
-          if (stored_symbol_name.substr(0, symbol_name.size()) == symbol_name) {
-            return std::make_pair(i_stored_symbol, false);
-          }
-        }
+      if (i_stored_symbol->name() == symbol_name) {
+        return std::make_pair(i_stored_symbol, false);
       }
     }