Update a few references to GHC 7.12

compiler/hsSyn/HsTypes.hs

@@ -607,7 +607,7 @@ Qualified currently behaves exactly as Implicit,
 but it is deprecated to use it for implicit quantification.
 In this case, GHC 7.10 gives a warning; see
 Note [Context quantification] in RnTypes, and Trac #4426.
-In GHC 7.12, Qualified will no longer bind variables
+In GHC 8.0, Qualified will no longer bind variables
 and this will become an error.
 
 The kind variables bound in the hsq_implicit field come both

libraries/base/Data/Version.hs

@@ -96,7 +96,7 @@ data Version =
         }
   deriving (Read,Show,Generic)
 {-# DEPRECATED versionTags "See GHC ticket #2496" #-}
--- TODO. Remove all references to versionTags in GHC 7.12 release.
+-- TODO. Remove all references to versionTags in GHC 8.0 release.
 
 instance Eq Version where
   v1 == v2  =  versionBranch v1 == versionBranch v2

libraries/template-haskell/Language/Haskell/TH/Lib.hs

@@ -471,7 +471,7 @@ closedTypeFamilyD tc tvs result injectivity eqns =
   do eqns1 <- sequence eqns
      return (ClosedTypeFamilyD (TypeFamilyHead tc tvs result injectivity) eqns1)
 
--- These were deprecated in GHC 7.12 with a plan to remove them in 7.14. If you
+-- These were deprecated in GHC 8.0 with a plan to remove them in 8.2. If you
 -- remove this check please also:
 --   1. remove deprecated functions
 --   2. remove CPP language extension from top of this module