cplus_demangle_type. This is the rev 1.50-1.51 change.
Our addr2line, etc.. would crash if used on C++ code that contains
certain symbol types. One example is
_ZN13PatternDriver23StringScalarDeleteValueC1ERKNS_25ConflateStringScalarValueERKNS_25AbstractStringScalarValueERKNS_12TemplateEnumINS_12pdcomplementELZNS_16complement_namesEELZNS_14COMPLEMENTENUMEEEE
