Use predefined options for universal, cxx11, and 32-bit options

:universal and :cxx11 are now handled directly, so we don't need to
always convert symbols to strings in this method. Symbols should be
reserved for future use.

Library/Homebrew/software_spec.rb

@@ -11,6 +11,12 @@ require 'patch'
 class SoftwareSpec
   extend Forwardable
 
+  PREDEFINED_OPTIONS = {
+    :universal => Option.new("universal", "Build a universal binary"),
+    :cxx11     => Option.new("c++11", "Build using C++11 mode"),
+    "32-bit"   => Option.new("32-bit", "Build 32-bit only"),
+  }
+
   attr_reader :name, :owner
   attr_reader :build, :resources, :patches, :options
   attr_reader :dependency_collector
@@ -75,20 +81,18 @@ class SoftwareSpec
     options.include?(name)
   end
 
-  def option name, description=nil
-    name = 'c++11' if name == :cxx11
-    name = name.to_s if Symbol === name
-    raise ArgumentError, "option name is required" if name.empty?
-    raise ArgumentError, "options should not start with dashes" if name.start_with?("-")
-
-    description ||= case name
-      when "universal" then "Build a universal binary"
-      when "32-bit" then "Build 32-bit only"
-      when "c++11" then "Build using C++11 mode"
-      else ""
+  def option(name, description="")
+    opt = PREDEFINED_OPTIONS.fetch(name) do
+      if Symbol === name
+        opoo "Passing arbitrary symbols to `option` is deprecated: #{name.inspect}"
+        puts "Symbols are reserved for future use, please pass a string instead"
+        name = name.to_s
       end
-
-    options << Option.new(name, description)
+      raise ArgumentError, "option name is required" if name.empty?
+      raise ArgumentError, "options should not start with dashes" if name.start_with?("-")
+      Option.new(name, description)
+    end
+    options << opt
   end
 
   def depends_on spec

Library/Homebrew/test/test_software_spec.rb

@@ -55,11 +55,6 @@ class SoftwareSpecTests < Homebrew::TestCase
     assert_raises(ArgumentError) { @spec.option("") }
   end
 
-  def test_option_accepts_symbols
-    @spec.option(:foo)
-    assert @spec.option_defined?("foo")
-  end
-
   def test_cxx11_option_special_case
     @spec.option(:cxx11)
     assert @spec.option_defined?("c++11")