llvm8: productivity/devtodo build failure

patrick@ is preparing to update the system compiler to LLVM 8.0.0.
A first step is updating libc++, libc++abi, libunwind.
(There's a diff at cvs:~patrick/abi.diff.2.)

I'm currently running a test build with this. One of the first
victims is productivity/devtodo:

ld: error: undefined symbol: std::__1::basic_ostream<char, std::__1::char_traits<char> >::operator<<(std::__1::basic_ostream<char, std::__1::char_traits<char> >& (*)(std::__1::basic_ostream<char, std::__1::char_traits<char> >&))
>>> referenced by TodoDB.cc
>>> TodoDB.o:(TodoDB::StreamColour::veryhigh(std::__1::basic_ostream<char, std::__1::char_traits<char> >&))

--
Christian "naddy" Weisgerber naddy@mips.inka.de