Userland: Disable Hackstudio and UE on x86_64

Userland/DevTools/CMakeLists.txt

@@ -1,5 +1,8 @@
-add_subdirectory(HackStudio)
 add_subdirectory(Inspector)
 add_subdirectory(Playground)
 add_subdirectory(Profiler)
-add_subdirectory(UserspaceEmulator)
+
+if("${SERENITY_ARCH}" STREQUAL "i686")
+	add_subdirectory(HackStudio)
+	add_subdirectory(UserspaceEmulator)
+endif()