haskell-stack: Fix build from source, support M1

- Fixed building from source.

  Due to recent update of aeson-2.0.0.0, stack can no longer be built
  with cabal-install. So I patched stack to freeze cabal dependencies
  using stackage 17.15 LTS.

- Add Apple Silicon support.

  HEAD version of stack has already been patched to support Apple
  Silicon. However, the next release containing that patch hasn't
  release yet. So I manually patched stack v2.7.3 to support Apple
  Silicon.

- Add llvm@12 as a dependency only on ARM

  All ghc versions before 9.2.1 requires LLVM Code Generator as a
  backend on ARM.

Fixes Homebrew#94796

Reference:
  commercialhaskell/stack#5562
  commercialhaskell/stack#5677

Formula/haskell-stack.rb

@@ -1,11 +1,36 @@
 class HaskellStack < Formula
   desc "Cross-platform program for developing Haskell projects"
   homepage "https://haskellstack.org/"
-  url "https://github.com/commercialhaskell/stack/archive/v2.7.3.tar.gz"
-  sha256 "37f4bc0177534782609ec3a67ec413548d3f2cabff7c4c0bc8a92a36e49c6877"
   license "BSD-3-Clause"
   head "https://github.com/commercialhaskell/stack.git", branch: "master"
 
+  stable do
+    url "https://github.com/commercialhaskell/stack/archive/v2.7.3.tar.gz"
+    sha256 "37f4bc0177534782609ec3a67ec413548d3f2cabff7c4c0bc8a92a36e49c6877"
+
+    # Due to recent update of aeson-2.0.0.0, stack can no longer be built with
+    # cabal-install. So I patched stack to freeze cabal dependencies using
+    # stackage 17.15 LTS.
+    #
+    # Reference:
+    #   https://github.com/commercialhaskell/stack/pull/5677
+    patch do
+      url "https://github.com/commercialhaskell/stack/commit/05951f21.patch?full_index=1"
+      sha256 "bc12787bffb450ac7246a34987e2d546325e6ecb0b5c75f6bfccf1b32f9693aa"
+    end
+
+    # HEAD version of stack has already been patched to support Apple Silicon.
+    # However, the next release containing that patch hasn't release yet. So I
+    # manually patched stack v2.7.3 to support Apple Silicon.
+    #
+    # Reference:
+    #   https://github.com/commercialhaskell/stack/pull/5562
+    patch do
+      url "https://github.com/commercialhaskell/stack/commit/32b80476.patch?full_index=1"
+      sha256 "36e09f68c951adb0b35a0d9a510c9c367554058d690c667636147f1cb483ef8d"
+    end
+  end
+
   livecheck do
     url :stable
     strategy :github_latest
@@ -21,12 +46,22 @@ class HaskellStack < Formula
 
   depends_on "cabal-install" => :build
   depends_on "ghc" => :build
+  # All ghc versions before 9.2.1 requires LLVM Code Generator as a backend on
+  # ARM. GHC 8.10.7 user manual recommend use LLVM 9 through 12 and we met some
+  # unknown issue with LLVM 13 before so conservatively use LLVM 12 here.
+  #
+  # References:
+  #   https://downloads.haskell.org/~ghc/8.10.7/docs/html/users_guide/8.10.7-notes.html
+  #   https://gitlab.haskell.org/ghc/ghc/-/issues/20559
+  depends_on "llvm@12" if Hardware::CPU.arm?
 
   uses_from_macos "zlib"
 
   def install
     system "cabal", "v2-update"
     system "cabal", "v2-install", *std_cabal_v2_args
+
+    bin.env_script_all_files libexec, PATH: "${PATH}:#{Formula["llvm@12"].opt_bin}" if Hardware::CPU.arm?
   end
 
   test do