Chaitin/Briggs register allocator

I seem to recall that LLVM had a Chaitin/Briggs register allocator, but looking
at today's source, I only see a Linear Scan and some basic block allocators.
Does anyone know if a Chaitin/Briggs allocator for LLVM exists and is available?

Peter

There isn't one available to the public as far as I know.

Evan