LLVM 2.1

I will be trying to deploy the puzzle solver on LLVM 2.1. I checked the code, and it does not seem to be a very easy task. It has changed a lot since 1.9. After that, I will have to add instruction folding, and then comes the really difficult part: to make the puzzle solver retargetable... don't cry for me Argentina... just to warm up, here is the list of passes invoked by the original LLVM 2.1 with linear scan, and here a list of the passes invoked with the simple register allocator.

The classes of registers in x86, and the new register numbering, as defined by LLVM 2.1 is given here