Merge pull request ruby#1 from nobu/patch-2

fake ALT_SEPARATOR

Author: unak

test/rubygems/test_gem_installer.rb

@@ -574,6 +574,9 @@ def test_generate_bin_symlink_update_remove_wrapper
   def test_generate_bin_symlink_win32
     old_win_platform = Gem.win_platform?
     Gem.win_platform = true
+    old_alt_separator = File::ALT_SEPARATOR
+    File.__send__(:remove_const, :ALT_SEPARATOR)
+    File::ALT_SEPARATOR = '\\'
     @installer.wrappers = false
     util_make_exec
     @installer.gem_dir = util_gem_dir
@@ -592,6 +595,8 @@ def test_generate_bin_symlink_win32
     wrapper = File.read installed_exec
     assert_match(/generated by RubyGems/, wrapper)
   ensure
+    File.__send__(:remove_const, :ALT_SEPARATOR)
+    File::ALT_SEPARATOR = old_alt_separator
     Gem.win_platform = old_win_platform
   end