Merge Bundler 2.1.2 from bundler/bundler.

[Misc #16449][ruby-core:96458]

lib/bundler/rubygems_integration.rb

@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+require "rubygems"
+
 module Bundler
   class RubygemsIntegration
     if defined?(Gem::Ext::Builder::CHDIR_MONITOR)

lib/bundler/version.rb

@@ -1,7 +1,7 @@
 # frozen_string_literal: false
 
 module Bundler
-  VERSION = "2.1.1".freeze
+  VERSION = "2.1.2".freeze
 
   def self.bundler_major_version
     @bundler_major_version ||= VERSION.split(".").first.to_i

spec/bundler/runtime/setup_spec.rb

@@ -1344,5 +1344,11 @@ end
       expect(last_command.stdboth).not_to include "FAIL"
       expect(err).to include "private method `require'"
     end
+
+    it "takes care of requiring rubygems" do
+      sys_exec("#{Gem.ruby} -I#{lib_dir} -e \"puts require('bundler/setup')\"", "RUBYOPT" => "--disable=gems")
+
+      expect(last_command.stdboth).to eq("true")
+    end
   end
 end