Comment 6 for bug 1763101

Here is the changelog which fix this.

2018-12-22 Jason Merrill <email address hidden>

        Remove support for demangling GCC 2.x era mangling schemes.
        * cplus-dem.c: Remove cplus_mangle_opname, cplus_demangle_opname,
        internal_cplus_demangle, and all subroutines.
        (libiberty_demanglers): Remove entries for ancient GNU (pre-3.0),
        Lucid, ARM, HP, and EDG demangling styles.
        (cplus_demangle): Remove 'work' variable. Don't call
        internal_cplus_demangle.