Intel have just open-sourced their "Functional Language Research Compiler", which currently only has a Haskell front-end.
https://github.com/IntelLabs/flrc
Interestingly, it's written in Standard ML.
I will need to have a closer look at the project, but this line from the README is discouraging:
>FLRC is open sourced as is. We at Intel Labs are no longer actively working on this compiler.
So it kind of looks like the research project served its goal and they're just throwing the code out there to anyone who cares, rather than actually working on another Haskell compiler.