Mark T11978a as broken due to #12019
Mark T11978a as broken due to #12019

Test Plan: `validate --slow`

Reviewers: austin

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D2536

GHC Trac Issues: #12019

shlevy/ghc,shlevy/ghc,sdiehl/ghc,shlevy/ghc,snoyberg/ghc,snoyberg/ghc,shlevy/ghc,mettekou/ghc,mettekou/ghc,ezyang/ghc,snoyberg/ghc,mettekou/ghc,sdiehl/ghc,ezyang/ghc,ezyang/ghc,snoyberg/ghc,ezyang/ghc,ezyang/ghc,olsner/ghc,snoyberg/ghc,olsner/ghc,mettekou/ghc,sdiehl/ghc,shlevy/ghc,snoyberg/ghc,sdiehl/ghc,shlevy/ghc,mettekou/ghc,shlevy/ghc,olsner/ghc,ezyang/ghc,ezyang/ghc,olsner/ghc,olsner/ghc,sdiehl/ghc,sdiehl/ghc,sdiehl/ghc,snoyberg/ghc,olsner/ghc,mettekou/ghc,olsner/ghc,mettekou/ghc