Add a macro for marking a function as noreturn
Add a macro for marking a function as noreturn

Kitware/sprokit,mathstuf/sprokit,linus-sherrill/sprokit,Kitware/sprokit,linus-sherrill/sprokit,linus-sherrill/sprokit,mathstuf/sprokit,Kitware/sprokit,linus-sherrill/sprokit,Kitware/sprokit,mathstuf/sprokit,mathstuf/sprokit