Always build bottles universally.

Library/Homebrew/extend/ARGV.rb

@@ -85,7 +85,7 @@ module HomebrewArgvExtension
   end
 
   def build_universal?
-    include? '--universal'
+    include? '--universal' or build_bottle?
   end
 
   # Request a 32-bit only build.

Library/Homebrew/extend/ENV.rb

@@ -377,7 +377,9 @@ Please take one of the following actions:
     append flags, xarch unless xarch.empty?
 
     if ARGV.build_bottle?
+      ohai "Building a universal bottle."
       append flags, '-mtune=' + map.fetch(:bottle) if map.has_key? :bottle
+      universal_binary
     else
       # Don't set -msse3 and older flags because -march does that for us
       append flags, '-march=' + map.fetch(Hardware.intel_family, default)