[rubygems/rubygems] Drop support for HP-UX

Support for HP-UX was dropped in Ruby in ruby/ruby#5457.

https://github.com/rubygems/rubygems/commit/a3a8df3582

lib/bundler/vendor/thor/lib/thor/shell/basic.rb

@@ -425,7 +425,7 @@ class Bundler::Thor
       end
 
       def unix?
-        RUBY_PLATFORM =~ /(aix|darwin|linux|(net|free|open)bsd|cygwin|solaris|irix|hpux)/i
+        RUBY_PLATFORM =~ /(aix|darwin|linux|(net|free|open)bsd|cygwin|solaris|irix)/i
       end
 
       def truncate(string, width)

lib/rubygems/platform.rb

@@ -97,7 +97,6 @@ class Gem::Platform
       when /darwin(\d+)?/ then          [ "darwin",    $1  ]
       when /^macruby$/ then             [ "macruby",   nil ]
       when /freebsd(\d+)?/ then         [ "freebsd",   $1  ]
-      when /hpux(\d+)?/ then            [ "hpux",      $1  ]
       when /^java$/, /^jruby$/ then     [ "java",      nil ]
       when /^java([\d.]*)/ then         [ "java",      $1  ]
       when /^dalvik(\d+)?$/ then        [ "dalvik",    $1  ]

test/rubygems/test_gem_platform.rb

@@ -86,7 +86,6 @@ class TestGemPlatform < Gem::TestCase
   def test_initialize
     test_cases = {
       "amd64-freebsd6" => ["amd64",     "freebsd", "6"],
-      "hppa2.0w-hpux11.31" => ["hppa2.0w", "hpux", "11"],
       "java" => [nil,         "java", nil],
       "jruby" => [nil, "java", nil],
       "universal-dotnet" => ["universal", "dotnet", nil],