Add haskell-8.1.20-0

Add package which installs Haskell 8.10.1, cabal 3.2.0.0 and hls
(haskell-language-server) 0.5.1 using ghcup [1]

We need libtinfo.so.6 at build time for ghcup and at run time for
haskell. The installed libncursesw.so is (hopefully) ABI compatible, so
add it to the package.

[1] https://gitlab.haskell.org/haskell/ghcup-hs#manual-install

haskell-8.10.2.build.sh

@@ -0,0 +1,65 @@
+#! /bin/bash
+
+PKG=haskell
+VERSION=8.10.2
+BUILD=0
+
+PREFIX=/pkg/$PKG-$VERSION-$BUILD
+if [ -n "$TESTING" ]; then PREFIX=/dev/shm/$PKG-$VERSION-$BUILD ; fi
+
+set -xe
+umask 022
+
+BUILD_TMPDIR=/dev/shm/$PKG-$VERSION-$BUILD.build.tmp
+test -d $BUILD_TMPDIR && ( chmod -R u+rwx $BUILD_TMPDIR || true ; rm -rf $BUILD_TMPDIR )
+mkdir -p $BUILD_TMPDIR/home
+export TMPDIR=$BUILD_TMPDIR
+export HOME=$BUILD_TMPDIR/home
+
+exec </dev/null
+
+mkdir -p $PREFIX
+cat >$PREFIX/profile <<-EOF
+	PATH=$PREFIX/bin:$PREFIX/.ghcup/bin:\$PATH
+	export LD_LIBRARY_PATH=$PREFIX/lib\${LD_LIBRARY_PATH:+:\$LD_LIBRARY_PATH}
+	if [ -d $PREFIX/.compatlibs ]; then export LD_LIBRARY_PATH=$PREFIX/.compatlibs\${LD_LIBRARY_PATH:+:\$LD_LIBRARY_PATH} ; fi
+EOF
+. $PREFIX/profile
+
+export MAKEFLAGS="-j $(nproc)"
+
+BUILDDIR=$PREFIX/build
+
+mkdir -p $BUILDDIR
+cd $BUILDDIR
+
+# https://www.haskell.org/platform/linux.html#linux-generic:
+# The recommended way to install the components of the generic platform is using ghcup to install ghc and cabal-install
+# and following the instructions at haskellstack.org to install stack
+
+# https://www.haskell.org/ghcup/:
+# if you don't like curl | sh, see other installation method
+# ---> https://gitlab.haskell.org/haskell/ghcup-hs#manual-install
+
+mkdir -p $PREFIX/bin
+test -e $PREFIX/bin/ghcup || wget -O  $PREFIX/bin/ghcup https://downloads.haskell.org/~ghcup/0.1.11/x86_64-linux-ghcup-0.1.11
+chmod +x $PREFIX/bin/ghcup
+
+mkdir -p $PREFIX/lib
+cp /usr/lib/libncursesw.so $PREFIX/lib/
+ln -sf libncursesw.so $PREFIX/lib/libtinfo.so.6
+
+export GHCUP_INSTALL_BASE_PREFIX=$PREFIX
+
+# ghcup list shows available and recomended versions
+
+ghcup install ghc $VERSION
+ghcup set ghc $VERSION
+
+ghcup install cabal 3.2.0.0
+ghcup set cabal 3.2.0.0
+
+ghcup install hls 0.5.1
+ghcup set hls 0.5.1
+
+exit