The -Wmismatched-new-delete detection of operator members of class
template instantiations is incomplete and overly simplistic, leading
to incorrect results and false positives.  Rather than reinventing
the wheel and parsing the mangled qualified names of the operators
the attached patch uses the demangler to compare their names.  Since
the code is only entered rarely (for user- defined overloads of
the operators, the cost of the demangling should be negligible in
most code bases).

Tested on x86_64-linux.

Martin