relnotes: Add note about #11744 and workaround
relnotes: Add note about #11744 and workaround

Test Plan: Read it

Reviewers: hvr, austin

Subscribers: carter, thomie

Differential Revision: https://phabricator.haskell.org/D2120

GHC Trac Issues: #11744

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