Ruby » Ruby master

fix null m_tbl

• class.c (class_instance_method_list): m_tbl in prepended
  class/module is NULL. [ruby-core:45915][Bug #6655]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@36236 b2dd03c8-39d4-4d8f-98ff-823fe69b080e