[commit: ghc] master's head updated: Improve the handling of used-once stuff (80989de)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

Branch 'master' now includes:

     838da6f Some refactoring of Demand and DmdAnal
     ba78bf1 Do not split void functions
     0558911 Assign strictness signatures to primitive operations
     869f69f Guarding against silly shifts
     80989de Improve the handling of used-once stuff