[8.6] ModOrigin: hidden module redefined

Summary

ghci crashes when I try to TAB-complete an import list

Steps to reproduce

I am typing "import Data.List (isS" and then press TAB

/opt/ghc/ghc-8.6.5/bin/ghci
GHCi, version 8.6.5: http://www.haskell.org/ghc/  :? for help
Prelude> import Data.List (isSghc: panic! (the 'impossible' happened)
  (GHC version 8.6.5 for x86_64-unknown-linux):
	ModOrigin: hidden module redefined

Expected behavior

suggest completions (or do nothing - as 8.6.4 does)

Environment

• GHC version used: 8.6.5

Optional:

• Operating System: GNU/Linux Fedora 30
• System Architecture: x86_64