Import r41148 from ruby trunk

This fixes deprecation warnings when creating YAML gemspecs.

Author: drbrain

History.txt

@@ -55,6 +55,8 @@ Bug fixes:
     Chris Morris.
   * Fixed default gem key and cert locations.  Pull request #511 by Samuel
     Cochran.
+  * Fix deprecation warnings when converting gemspecs to yaml.  Ruby commit
+    r41148 by Yui Naruse
 
 === 2.0.2 / 2013-03-06
 

lib/rubygems/specification.rb

@@ -2268,7 +2268,7 @@ def to_yaml(opts = {}) # :nodoc:
         require 'rubygems/psych_tree'
       end
 
-      builder = Gem::NoAliasYAMLTree.new({})
+      builder = Gem::NoAliasYAMLTree.create
       builder << self
       ast = builder.tree