Summary:
This is another fallout from 8b007abb
should fix Trac #14264. I am not sure if this is
complete. It does however allow me to build an iOS
LLVM cross compiler.

Reviewers: bgamari, trofi, austin, simonmar

Reviewed By: trofi

Subscribers: rwbarton, thomie

GHC Trac Issues: #14264

Differential Revision: https://phabricator.haskell.org/D4014