[rubygems/rubygems] Fix RubyGems warnings about missing shebang

https://github.com/rubygems/rubygems/commit/362c960497

spec/bundler/commands/binstubs_spec.rb

@@ -115,7 +115,8 @@ RSpec.describe "bundle binstubs <gem>" do
           build_gem "prints_loaded_gems", "1.0" do |s|
             s.executables = "print_loaded_gems"
             s.bindir = "exe"
-            s.write "exe/print_loaded_gems", <<-R
+            s.write "exe/print_loaded_gems", <<~R
+              #!/usr/bin/env ruby
               specs = Gem.loaded_specs.values.reject {|s| s.default_gem? }
               puts specs.map(&:full_name).sort.inspect
             R

spec/bundler/support/builders.rb

@@ -153,7 +153,7 @@ module Spec
 
         build_gem "bundler", "0.9" do |s|
           s.executables = "bundle"
-          s.write "bin/bundle", "puts 'FAIL'"
+          s.write "bin/bundle", "#!/usr/bin/env ruby\nputs 'FAIL'"
         end
 
         # The bundler 0.8 gem has a rubygems plugin that always loads :(