8.8.1-alpha2: fail is not a (visible) method of class Monad

Summary

utils/genprimopcode/ParserM.hs:45:5: error:
    ‘fail’ is not a (visible) method of class ‘Monad’
   |
45 |     fail err = ParserM $ \_ _ -> Left err

Steps to reproduce

Built 8.8.1-alpha1 with ghc 8.6.5 and installed it. Then tried to build it again with 8.8.1-alpha1 and got the above.

Expected behavior

GHC needs to be able to build itself. Solution is probably to add a MonadFail instance for ParserM.

Environment

• GHC version used: 8.8.1-alpha1 from source code tarball.

Optional:

• Operating System: Linux
• System Architecture: amd64