Use prefix notation in pprIfaceDecl for IfaceIds
Use prefix notation in pprIfaceDecl for IfaceIds

(cherry picked from commit 5908a7427abd35264f5bafd5bf7bce3a0c9dde8e)

hferreiro/replay,hferreiro/replay,hferreiro/replay,hferreiro/replay,hferreiro/replay,hferreiro/replay,lukexi/ghc-7.8-arm64,lukexi/ghc-7.8-arm64,lukexi/ghc-7.8-arm64,lukexi/ghc-7.8-arm64,lukexi/ghc-7.8-arm64,hferreiro/replay