* vm_method.c (rb_method_entry_make): fix WB miss.
  Note that rb_method_entry_t::klass is not constified.
  We may  constify this field.
* test/ruby/test_alias.rb: add a test.



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@44234 b2dd03c8-39d4-4d8f-98ff-823fe69b080e