Make llvm_unreachable take an optional string, thus moving the cerr<< out of
line.
LLVM_UNREACHABLE is now a simple wrapper that makes the message go away for
NDEBUG builds.
llvm-svn: 75379
logical/sane approach to organizing all of the stuff that goes into writing out
DWARF information. Honestly? even this is too complex for what it's supposed to
be doing.
Trivia: It *looks* like there would be functionality changes, however there aren't!
llvm-svn: 71821