CMakeLists: Embed macOS Updater app inside DolphinQt

I accomplish this by adding a new step where a copy of the DolphinQt bundle is created, and then the Updater is inserted into it.

Source/Core/CMakeLists.txt

@@ -30,3 +30,59 @@ endif()
 if (WIN32 AND ENABLE_AUTOUPDATE)
   add_subdirectory(WinUpdater)
 endif()
+
+if (APPLE AND ENABLE_QT)
+  set(DOLPHIN_MAC_BUNDLE "${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/Dolphin.app")
+
+  add_custom_target(build_final_bundle ALL
+    COMMAND ${CMAKE_COMMAND} -E remove_directory
+    ${DOLPHIN_MAC_BUNDLE}
+    
+    COMMAND cp -R
+    ${CMAKE_RUNTIME_OUTPUT_DIRECTORY}/DolphinQt.app
+    ${DOLPHIN_MAC_BUNDLE}
+
+    # HACK: The Updater does not support setting the executable bit on new files,
+    # so don't use the new executable name, and instead continue to use "Dolphin".
+    COMMAND ${CMAKE_COMMAND} -E rename
+    ${DOLPHIN_MAC_BUNDLE}/Contents/MacOS/DolphinQt
+    ${DOLPHIN_MAC_BUNDLE}/Contents/MacOS/Dolphin
+
+    COMMAND plutil
+    -replace CFBundleExecutable -string Dolphin
+    ${DOLPHIN_MAC_BUNDLE}/Contents/Info.plist
+    
+    DEPENDS dolphin-emu)
+  
+  if (ENABLE_AUTOUPDATE)
+    add_dependencies(build_final_bundle MacUpdater)
+
+    add_custom_command(TARGET build_final_bundle
+      POST_BUILD
+      COMMAND ${CMAKE_COMMAND} -E make_directory
+      "${DOLPHIN_MAC_BUNDLE}/Contents/Helpers"
+
+      COMMAND cp -R
+      "$<TARGET_BUNDLE_DIR:MacUpdater>"
+      "${DOLPHIN_MAC_BUNDLE}/Contents/Helpers/Dolphin Updater.app")
+
+    if (MACOS_CODE_SIGNING)
+      add_custom_command(TARGET build_final_bundle
+        POST_BUILD
+        COMMAND "${CMAKE_SOURCE_DIR}/Tools/mac-codesign.sh"
+        "-t"
+        "${MACOS_CODE_SIGNING_IDENTITY}"
+        "${DOLPHIN_MAC_BUNDLE}/Contents/Helpers/Dolphin Updater.app")
+    endif()
+  endif()
+
+  if (MACOS_CODE_SIGNING)
+    add_custom_command(TARGET build_final_bundle
+      POST_BUILD
+      COMMAND "${CMAKE_SOURCE_DIR}/Tools/mac-codesign.sh"
+      "-t"
+      "-e" "${CMAKE_SOURCE_DIR}/Source/Core/DolphinQt/DolphinEmu$<$<CONFIG:Debug>:Debug>.entitlements"
+      "${MACOS_CODE_SIGNING_IDENTITY}"
+      "${DOLPHIN_MAC_BUNDLE}")
+  endif()
+endif()