Revert "Chect what remains in TMPDIR"

This reverts commit 7bdb999.

I think I confirmed the mechanism. GCC (invoked by MJIT) creates a
temporary file in TMPDIR, which prevents rm_rf from removing the
directory.

test/rubygems/helper.rb

@@ -466,18 +466,13 @@ def teardown
     Dir.chdir @current_dir
 
     # Prevent a race condition on removing TMPDIR being written by MJIT
-    #if defined?(RubyVM::MJIT.enabled?) && RubyVM::MJIT.enabled?
-    #  RubyVM::MJIT.pause(wait: false)
-    #end
-    begin
-      FileUtils.rm_rf @tempdir
-    ensure
-      # mame: Temporal code for debugging. Let me confirm what remains in the directory
-      pp Dir.glob(File.join(@tempdir, "**", "{.*,*}")) if $!
-    end
-    #if defined?(RubyVM::MJIT.enabled?) && RubyVM::MJIT.enabled?
-    #  RubyVM::MJIT.resume
-    #end
+    if defined?(RubyVM::MJIT.enabled?) && RubyVM::MJIT.enabled?
+      RubyVM::MJIT.pause(wait: false)
+    end
+    FileUtils.rm_rf @tempdir
+    if defined?(RubyVM::MJIT.enabled?) && RubyVM::MJIT.enabled?
+      RubyVM::MJIT.resume
+    end
 
     ENV.replace(@orig_env)