Move getting formula names from bottles to method.

Library/Homebrew/bottles.rb

@@ -89,3 +89,10 @@ def bottle_tag
     Hardware::CPU.type == :ppc ? Hardware::CPU.family : MacOS.cat
   end
 end
+
+def bottle_filename_formula_name filename
+  version = Version.parse(filename).to_s
+  path = Pathname.new filename
+  basename = path.basename.to_s
+  basename.rpartition("-#{version}").first
+end

Library/Homebrew/formulary.rb

@@ -59,9 +59,7 @@ class Formulary
   class BottleLoader < FormulaLoader
     def initialize bottle_name
       @bottle_filename = Pathname(bottle_name).realpath
-      version = Version.parse(@bottle_filename).to_s
-      bottle_basename = @bottle_filename.basename.to_s
-      name_without_version = bottle_basename.rpartition("-#{version}").first
+      name_without_version = bottle_filename_formula_name @bottle_filename
       if name_without_version.empty?
         if ARGV.homebrew_developer?
           opoo "Add a new version regex to version.rb to parse this filename."