haskell.compiler.ghc9123: apply patch for incorrect subword division

This is a simple revert, so easy to apply. Unfortunately, it seems
like it'll be some time until 9.12.4 is released…

Debian and Fedora seem to have opted for patching this issue, too.

pkgs/development/compilers/ghc/common-hadrian.nix

@@ -291,6 +291,14 @@
               hash = "sha256-Vr5wkiSE1S5e+cJ8pWUvG9KFpxtmvQ8wAy08ElGNp5E=";
             })
           ]
+      # Fix subword division regression in 9.12.3 https://gitlab.haskell.org/ghc/ghc/-/merge_requests/15264
+      ++ lib.optionals (version == "9.12.3") [
+        (fetchpatch {
+          name = "ghc-9.12.3-fix-subword-division.patch";
+          url = "https://gitlab.haskell.org/ghc/ghc/-/commit/65370007e2d9f1976fbcfbb514917fb111117148.patch";
+          hash = "sha256-GMnD0StBTRynl2Lels1L0u1bo7HscLGPUAv+rTJ98QQ=";
+        })
+      ]
       # Fixes stack overrun in rts which crashes an process whenever
       # freeHaskellFunPtr is called with nixpkgs' hardening flags.
       # https://gitlab.haskell.org/ghc/ghc/-/issues/25485 krank:ignore-line