Use stub executables generated by RubyGems istead of original executables.

It resolved the conflict issues when invoking `gem i rdoc` and the binstub
issues with Bundler and Rails.

  [Bug #5060][ruby-core:38257][Fix GH-2023]

  * https://github.com/rubygems/rubygems/pull/2338
  * https://github.com/heroku/heroku-buildpack-ruby/issues/829

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65963 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

bin/bundle_ruby

@@ -1,60 +1,27 @@
 #!/usr/bin/env ruby
-# frozen_string_literal: true
+#
+# This file was generated by RubyGems.
+#
+# The application 'bundler' is installed as part of a gem, and
+# this file is here to facilitate running it.
+#
 
-require "bundler/shared_helpers"
+require 'rubygems'
 
-Bundler::SharedHelpers.major_deprecation(3, "the bundle_ruby executable has been removed in favor of `bundle platform --ruby`")
+version = ">= 0.a"
 
-Signal.trap("INT") { exit 1 }
-
-require "bundler/errors"
-require "bundler/ruby_version"
-require "bundler/ruby_dsl"
-
-module Bundler
-  class Dsl
-    include RubyDsl
-
-    attr_accessor :ruby_version
-
-    def initialize
-      @ruby_version = nil
-    end
-
-    def eval_gemfile(gemfile, contents = nil)
-      contents ||= File.open(gemfile, "rb", &:read)
-      instance_eval(contents, gemfile.to_s, 1)
-    rescue SyntaxError => e
-      bt = e.message.split("\n")[1..-1]
-      raise GemfileError, ["Gemfile syntax error:", *bt].join("\n")
-    rescue ScriptError, RegexpError, NameError, ArgumentError => e
-      e.backtrace[0] = "#{e.backtrace[0]}: #{e.message} (#{e.class})"
-      STDERR.puts e.backtrace.join("\n       ")
-      raise GemfileError, "There was an error in your Gemfile," \
-        " and Bundler cannot continue."
-    end
-
-    def source(source, options = {})
-    end
-
-    def gem(name, *args)
-    end
-
-    def group(*args)
-    end
+if ARGV.first
+  str = ARGV.first
+  str = str.dup.force_encoding("BINARY") if str.respond_to? :force_encoding
+  if str =~ /\A_(.*)_\z/ and Gem::Version.correct?($1) then
+    version = $1
+    ARGV.shift
   end
 end
 
-dsl = Bundler::Dsl.new
-begin
-  dsl.eval_gemfile(Bundler::SharedHelpers.default_gemfile)
-  ruby_version = dsl.ruby_version
-  if ruby_version
-    puts ruby_version
-  else
-    puts "No ruby version specified"
-  end
-rescue Bundler::GemfileError => e
-  puts e.message
-  exit(-1)
+if Gem.respond_to?(:activate_bin_path)
+load Gem.activate_bin_path('bundler', 'bundle_ruby', version)
+else
+gem "bundler", version
+load Gem.bin_path("bundler", "bundle_ruby", version)
 end