Don't barf on 'HsSpliceTy' (#745)
Don't barf on 'HsSpliceTy' (#745)

This handles 'HsSpliceTy's by replacing them with what they expand to.
IIUC everything that is happening, 'renameHsSpliceTy' should not be
able to fail for the inputs we feed it from GHC.

This fixes #574.

haskell/haddock,haskell/haddock,haskell/haddock,haskell/haddock,haskell/haddock