rbinstall.rb: add date

* tool/rbinstall.rb (Gem::Specification#initialize): default date to
  RUBY_RELEASE_DATE.  [ruby-core:57072] [Bug #8878]
* tool/rbinstall.rb (Gem::Specification#to_ruby): add date.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@42890 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,10 @@
+Mon Sep  9 09:14:58 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* tool/rbinstall.rb (Gem::Specification#initialize): default date to
+	  RUBY_RELEASE_DATE.  [ruby-core:57072] [Bug #8878]
+
+	* tool/rbinstall.rb (Gem::Specification#to_ruby): add date.
+
 Sun Sep  8 16:01:54 2013  Tanaka Akira  <akr@fsij.org>
 
 	* rational.c (f_gcd): Relax the condition to use GMP.

tool/rbinstall.rb

@@ -560,6 +560,7 @@ module Gem
       super
       yield(self) if defined?(yield)
       self.executables ||= []
+      self.date ||= RUBY_RELEASE_DATE
     end
 
     def self.load(path)
@@ -573,6 +574,7 @@ module Gem
 Gem::Specification.new do |s|
   s.name = #{name.dump}
   s.version = #{version.dump}
+  s.date = #{date.dump}
   s.summary = #{summary.dump}
   s.description = #{description.dump}
   s.homepage = #{homepage.dump}