Added bundler as default gems. Revisit [Feature #12733]

* bin/*, lib/bundler/*, lib/bundler.rb, spec/bundler, man/*:
    Merge from latest stable branch of bundler/bundler repository and
    added workaround patches. I will backport them into upstream.
  * common.mk, defs/gmake.mk: Added `test-bundler` task for test suite
    of bundler.
  * tool/sync_default_gems.rb: Added sync task for bundler.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@65509 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

spec/bundler/commands/issue_spec.rb

@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+RSpec.describe "bundle issue" do
+  it "exits with a message" do
+    install_gemfile <<-G
+      source "file://#{gem_repo1}"
+      gem "rails"
+    G
+
+    bundle "issue"
+    expect(out).to include "Did you find an issue with Bundler?"
+    expect(out).to include "## Environment"
+    expect(out).to include "## Gemfile"
+    expect(out).to include "## Bundle Doctor"
+  end
+end