Add a GitHub Actions workflow for ARM64

This also updates release.hs to use a more recent resolver, since
otherwise we'll have trouble on ARM64 with conflicting LLVM
installations. Unlike #5552, I took the simple workaround here of
installing GHC 8.6.5 in addition to the more recent GHC needed by
release.hs.

.github/workflows/arm64-release.yml

@@ -0,0 +1,33 @@
+name: ARM64 Release
+
+on:
+  pull_request:
+  push:
+    branches:
+      - master
+      - stable
+      - rc/**
+    tags:
+      - '**'
+  workflow_dispatch:
+
+jobs:
+  arm64:
+    name: Unit tests
+    runs-on: [self-hosted, linux, ARM64]
+    steps:
+      - name: Clone project
+        uses: actions/checkout@v2
+      - shell: bash
+        run: |
+          set -ex
+          mkdir -p ~/.local/bin
+          stack upgrade || curl -sSL https://github.com/commercialhaskell/stack/releases/download/v2.7.1/stack-2.7.1-linux-aarch64.bin > ~/.local/bin/stack
+          chmod +x ~/.local/bin/stack
+          ~/.local/bin/stack etc/scripts/release.hs build
+
+      - name: Upload bindist
+        uses: actions/upload-artifact@v2
+        with:
+          name: ${{ runner.os }}
+          path: _release/stack-*

etc/scripts/release.hs

@@ -1,5 +1,5 @@
 {- stack script
-    --resolver lts-14.27
+    --resolver lts-17.10
     --install-ghc
     --ghc-options -Wall
     --package Cabal
@@ -36,6 +36,7 @@ import Distribution.Text
 import Distribution.System
 import Distribution.Package
 import Distribution.PackageDescription hiding (options)
+import Distribution.Utils.ShortText (fromShortText)
 import Distribution.Verbosity
 import System.Console.GetOpt
 import System.Directory
@@ -152,6 +153,13 @@ rules global@Global{..} args = do
               , " option to continue anyway. Output:\n"
               , show dirty
               ]
+
+        -- Integration tests still depend on GHC 8.6.5
+        () <- cmd
+            [gProjectRoot </> releaseBinDir </> binaryName </> stackExeFileName]
+            ["setup"]
+            ["ghc-8.6.5"]
+
         () <- cmd
             [gProjectRoot </> releaseBinDir </> binaryName </> stackExeFileName]
             (stackArgs global)
@@ -214,8 +222,8 @@ rules global@Global{..} args = do
                             (command_ [] "c:\\Program Files\\Microsoft SDKs\\Windows\\v7.1\\Bin\\signtool.exe"
                                 ["sign"
                                 ,"/v"
-                                ,"/d", synopsis gStackPackageDescription
-                                ,"/du", homepage gStackPackageDescription
+                                ,"/d", fromShortText $ synopsis gStackPackageDescription
+                                ,"/du", fromShortText $ homepage gStackPackageDescription
                                 ,"/n", certName
                                 ,"/t", "http://timestamp.verisign.com/scripts/timestamp.dll"
                                 ,out])