[T16199] Adds a verify-packages script

utils/verify-release/verify-packages.sh

+#!/bin/bash
+#
+# This script will verify that the packages in ghc,
+# correspond to packages on hackage.
+rm -fR ghc-packages hackage-packages package-diffs
+mkdir -p ghc-packages hackage-packages package-diffs
+# We'll skip Cabal and tarballs, while looking only at packages in libraries
+# that we reference as gitmodules.
+for lib in $(git submodule status|grep libraries|grep -v tarballs|grep -v Cabal|awk -F\  '{ print $2 }'); do
+    (cd $lib && cabal new-sdist -o ../../ghc-packages);
+done
+
+for pkg in $(cd ghc-packages && ls *.tar.gz); do
+    PKG=${pkg%%.tar.gz}
+    (cd hackage-packages && cabal get --pristine ${PKG})
+    (cd hackage-packages/${PKG} && git init && git add . && git commit -q -m "hackage packages" && rm -fR *)
+    (cd hackage-packages && tar xzf ../ghc-packages/$pkg)
+    (cd hackage-packages/${PKG} && git -c core.fileMode=false diff > ../$PKG.patch)
+done
+find hackage-packages -name "*.patch" -not -empty -type f -print -exec false {} +