Problem is in cxa_demangle.cpp, "parse_encoding" method.
Method checks previously demangled characters to detect whether template arguments were parsed, and whether it can proceed to type parsing.
So, method misrecognises ">" as template closing tag. It wouldn't be good if we check that closing tag is not a tail of "operator>", since it won't solve whole problem. It still will conflict with constructions like "<despicable_operator>".
Current patch fixes this problem by adding extra space into demangling sequence for GT operator: "operator> ".
Though generally, it would be good if we will keep parsing stack information somewhere.