This file is copied from gcc, revision 244567: https://gcc.gnu.org/viewcvs/gcc/trunk/libiberty/testsuite/demangle-expected?revision=244567&view=markup
It is licensed under the GNU Lesser General Public License Version 2.1: https://gcc.gnu.org/viewcvs/gcc/trunk/libiberty/COPYING.LIB?revision=184997&view=markup
We include it here under the "mere aggregation" clause.