Add Outputable ShowHowMuch
Add Outputable ShowHowMuch

I needed this instance when debugging, so I thought I'd add
it permanently.

snoyberg/ghc,snoyberg/ghc,vTurbine/ghc,olsner/ghc,ezyang/ghc,olsner/ghc,ezyang/ghc,mettekou/ghc,sdiehl/ghc,sdiehl/ghc,vTurbine/ghc,vikraman/ghc,olsner/ghc,sgillespie/ghc,olsner/ghc,shlevy/ghc,vikraman/ghc,sgillespie/ghc,ezyang/ghc,ezyang/ghc,mettekou/ghc,sgillespie/ghc,ezyang/ghc,sdiehl/ghc,shlevy/ghc,snoyberg/ghc,shlevy/ghc,vikraman/ghc,sgillespie/ghc,mettekou/ghc,vikraman/ghc,mettekou/ghc,mettekou/ghc,sdiehl/ghc,snoyberg/ghc,vTurbine/ghc,vTurbine/ghc,snoyberg/ghc,ezyang/ghc,sdiehl/ghc,shlevy/ghc,sgillespie/ghc,olsner/ghc,vikraman/ghc,olsner/ghc,vikraman/ghc,sdiehl/ghc,ezyang/ghc,shlevy/ghc,vTurbine/ghc,vTurbine/ghc,sdiehl/ghc,mettekou/ghc,sgillespie/ghc,shlevy/ghc,mettekou/ghc,olsner/ghc,snoyberg/ghc,shlevy/ghc,vikraman/ghc,snoyberg/ghc,vTurbine/ghc,sgillespie/ghc