Bump to GHC 8.0

* Raise minimum GHC version to 8.0 so we'll be able to define
  `Lift` instances, avoid certain conditional definitions, etc.

* Raise Cabal version for tests to 2.2; use `common` stanzas.

Author: treeowl

.github/workflows/haskell-ci.yml

@@ -8,9 +8,9 @@
 #
 # For more information, see https://github.com/haskell-CI/haskell-ci
 #
-# version: 0.13.20211111
+# version: 0.13.20211030
 #
-# REGENDATA ("0.13.20211111",["github","--config=cabal.haskell-ci","cabal.project"])
+# REGENDATA ("0.13.20211030",["github","--config=cabal.haskell-ci","cabal.project"])
 #
 name: Haskell-CI
 on:
@@ -24,8 +24,6 @@ jobs:
   linux:
     name: Haskell-CI - Linux - ${{ matrix.compiler }}
     runs-on: ubuntu-18.04
-    timeout-minutes:
-      60
     container:
       image: buildpack-deps:bionic
     continue-on-error: ${{ matrix.allow-failure }}
@@ -72,21 +70,6 @@ jobs:
             compilerVersion: 8.0.2
             setup-method: hvr-ppa
             allow-failure: false
-          - compiler: ghc-7.10.3
-            compilerKind: ghc
-            compilerVersion: 7.10.3
-            setup-method: hvr-ppa
-            allow-failure: false
-          - compiler: ghc-7.8.4
-            compilerKind: ghc
-            compilerVersion: 7.8.4
-            setup-method: hvr-ppa
-            allow-failure: false
-          - compiler: ghc-7.6.3
-            compilerKind: ghc
-            compilerVersion: 7.6.3
-            setup-method: hvr-ppa
-            allow-failure: false
       fail-fast: false
     steps:
       - name: apt
@@ -136,7 +119,7 @@ jobs:
           HCNUMVER=$(${HC} --numeric-version|perl -ne '/^(\d+)\.(\d+)\.(\d+)(\.(\d+))?$/; print(10000 * $1 + 100 * $2 + ($3 == 0 ? $5 != 1 : $3))')
           echo "HCNUMVER=$HCNUMVER" >> "$GITHUB_ENV"
           echo "ARG_TESTS=--enable-tests" >> "$GITHUB_ENV"
-          if [ $((HCNUMVER >= 70800 && HCNUMVER < 90200)) -ne 0 ] ; then echo "ARG_BENCH=--enable-benchmarks" >> "$GITHUB_ENV" ; else echo "ARG_BENCH=--disable-benchmarks" >> "$GITHUB_ENV" ; fi
+          if [ $((HCNUMVER < 90200)) -ne 0 ] ; then echo "ARG_BENCH=--enable-benchmarks" >> "$GITHUB_ENV" ; else echo "ARG_BENCH=--disable-benchmarks" >> "$GITHUB_ENV" ; fi
           echo "HEADHACKAGE=false" >> "$GITHUB_ENV"
           echo "ARG_COMPILER=--$HCKIND --with-compiler=$HC" >> "$GITHUB_ENV"
           echo "GHCJSARITH=0" >> "$GITHUB_ENV"
@@ -166,10 +149,6 @@ jobs:
           repository hackage.haskell.org
             url: http://hackage.haskell.org/
           EOF
-          cat >> $CABAL_CONFIG <<EOF
-          program-default-options
-            ghc-options: $GHCJOBS +RTS -M3G -RTS
-          EOF
           cat $CABAL_CONFIG
       - name: versions
         run: |

containers-tests/benchmarks/IntSet.hs

@@ -8,9 +8,6 @@ import Control.Exception (evaluate)
 import Gauge (bench, defaultMain, whnf)
 import Data.List (foldl')
 import Data.Monoid (Sum(..))
-#if !MIN_VERSION_base(4,8,0)
-import Data.Foldable (foldMap)
-#endif
 import qualified Data.IntSet as IS
 -- benchmarks for "instance Ord IntSet"
 -- uses IntSet as keys of maps, and elements of sets

containers-tests/benchmarks/Map.hs

@@ -13,9 +13,7 @@ import qualified Data.Map.Strict as MS
 import Data.Map (alterF)
 import Data.Maybe (fromMaybe)
 import Data.Functor ((<$))
-#if __GLASGOW_HASKELL__ >= 708
 import Data.Coerce
-#endif
 import Prelude hiding (lookup)
 
 main = do
@@ -134,11 +132,7 @@ atIns xs m = foldl' (\m (k, v) -> runIdentity (alterF (\_ -> Identity (Just v))
 
 newtype Ident a = Ident { runIdent :: a }
 instance Functor Ident where
-#if __GLASGOW_HASKELL__ >= 708
   fmap = coerce
-#else
-  fmap f (Ident a) = Ident (f a)
-#endif
 
 atInsNoRules :: [(Int, Int)] -> M.Map Int Int -> M.Map Int Int
 atInsNoRules xs m = foldl' (\m (k, v) -> runIdent (alterF (\_ -> Ident (Just v)) k m)) m xs