Rename test classes to allow stable test count when running test-all -j

[Fix GH-1763]

From: MSP-Greg <MSP-Greg@users.noreply.github.com>

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62738 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

Author: nobu

test/fileutils/test_dryrun.rb

@@ -8,7 +8,7 @@
 class TestFileUtilsDryRun < Test::Unit::TestCase
 
   include FileUtils::DryRun
-  include TestFileUtils::Visibility
+  include TestFileUtilsInc::Visibility
 
   def setup
     super

test/fileutils/test_nowrite.rb

@@ -8,7 +8,7 @@
 class TestFileUtilsNoWrite < Test::Unit::TestCase
 
   include FileUtils::NoWrite
-  include TestFileUtils::Visibility
+  include TestFileUtilsInc::Visibility
 
   def setup
     super

test/fileutils/test_verbose.rb

@@ -8,7 +8,7 @@
 class TestFileUtilsVerbose < Test::Unit::TestCase
 
   include FileUtils::Verbose
-  include TestFileUtils::Visibility
+  include TestFileUtilsInc::Visibility
 
   def setup
     super

test/fileutils/visibility_tests.rb

@@ -2,14 +2,14 @@
 require 'test/unit'
 require 'fileutils'
 
-class TestFileUtils < Test::Unit::TestCase
+class TestFileUtilsInc < Test::Unit::TestCase
 end
 
 ##
 # These tests are reused in the FileUtils::Verbose, FileUtils::NoWrite and
 # FileUtils::DryRun tests
 
-module TestFileUtils::Visibility
+module TestFileUtilsInc::Visibility
 
   FileUtils::METHODS.each do |m|
     define_method "test_singleton_visibility_#{m}" do