Merge pull request #5860 from jonchang/pretty-arch

arch: actually show required architecture

Library/Homebrew/requirements/arch_requirement.rb

@@ -18,4 +18,8 @@ class ArchRequirement < Requirement
   def message
     "This formula requires an #{@arch} architecture."
   end
+
+  def display_s
+    "#{@arch} architecture"
+  end
 end