[cfe-dev] Diagnostics are now TableGenerated

[Sebastian Redl]

Hi,

Once the llvm.org server comes back up, I'll commit the changes that
switch Clang from using .def files for the diagnostics to .td tablegen
files. It compiles, all tests pass, and there aren't any spurious
rebuilds. (Except perhaps for CMake users.)

>From now on, make sure you modify the .td files, and not the .def files
that SVN might not delete, or the generated .inc files.

Build system people, can you please validate the changes I've done? It's
a bit confusing, and I'm not sure if I've done it all correctly.

Win32 or other CMake users, please check if what I've done works. I
haven't had the chance to test it yet.

Sebastian