Give a more verbose error message when desugaring a HsTypeOut
Give a more verbose error message when desugaring a HsTypeOut

Reviewers: austin, bgamari

Reviewed By: bgamari

Subscribers: thomie

Differential Revision: https://phabricator.haskell.org/D1826

(cherry picked from commit 7cd37c599fa83817b51234ff2ff79e4e4896b117)

GaloisInc/halvm-ghc,GaloisInc/halvm-ghc,GaloisInc/halvm-ghc,GaloisInc/halvm-ghc,GaloisInc/halvm-ghc,GaloisInc/halvm-ghc,GaloisInc/halvm-ghc