config: show homebrew ruby for all system (#492)

Library/Homebrew/extend/os/mac/system_config.rb

@@ -28,14 +28,8 @@ class SystemConfig
       "#{MacOS::XQuartz.version} => #{describe_path(MacOS::XQuartz.prefix)}"
     end
 
-    def describe_system_ruby
-      s = ""
-      case RUBY_VERSION
-      when /^1\.[89]/, /^2\.0/
-        s << "#{RUBY_VERSION}-p#{RUBY_PATCHLEVEL}"
-      else
-        s << RUBY_VERSION
-      end
+    def describe_homebrew_ruby
+      s = describe_homebrew_ruby_version
 
       if RUBY_PATH.to_s !~ %r{^/System/Library/Frameworks/Ruby.framework/Versions/[12]\.[089]/usr/bin/ruby}
         s << " => #{RUBY_PATH}"
@@ -45,7 +39,6 @@ class SystemConfig
 
     def dump_verbose_config(f = $stdout)
       dump_generic_verbose_config(f)
-      f.puts "System Ruby: #{describe_system_ruby}"
       f.puts "OS X: #{MacOS.full_version}-#{kernel}"
       f.puts "Xcode: #{xcode ? xcode : "N/A"}"
       f.puts "CLT: #{clt ? clt : "N/A"}"

Library/Homebrew/system_config.rb

@@ -85,6 +85,19 @@ class SystemConfig
       end
     end
 
+    def describe_homebrew_ruby_version
+      case RUBY_VERSION
+      when /^1\.[89]/, /^2\.0/
+        "#{RUBY_VERSION}-p#{RUBY_PATCHLEVEL}"
+      else
+        RUBY_VERSION
+      end
+    end
+
+    def describe_homebrew_ruby
+      "#{describe_homebrew_ruby_version} => #{RUBY_PATH}"
+    end
+
     def hardware
       return if Hardware::CPU.type == :dunno
       "CPU: #{Hardware.cores_as_words}-core #{Hardware::CPU.bits}-bit #{Hardware::CPU.family}"
@@ -129,6 +142,7 @@ class SystemConfig
       f.puts "HOMEBREW_CELLAR: #{HOMEBREW_CELLAR}"
       f.puts "HOMEBREW_BOTTLE_DOMAIN: #{BottleSpecification::DEFAULT_DOMAIN}"
       f.puts hardware if hardware
+      f.puts "Homebrew Ruby: #{describe_homebrew_ruby}"
       f.puts "GCC-4.0: build #{gcc_40}" if gcc_40
       f.puts "GCC-4.2: build #{gcc_42}" if gcc_42
       f.puts "Clang: #{clang ? "#{clang} build #{clang_build}" : "N/A"}"