[ruby-cvs:69414] nagachika:r62233 (ruby_2_4): merge revision(s) 60980, 60984: [Backport #14070]

[nagachika at ruby-lang.org]

nagachika	2018-02-05 23:05:52 +0900 (Mon, 05 Feb 2018)

  New Revision: 62233

  https://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=revision&revision=62233

  Log:
    merge revision(s) 60980,60984: [Backport #14070]
    
    Modules should not have subclasses.
    
    When refining a module, the module was set to the superclass of its refinement,
    and a segmentation fault occurred.
    The superclass of the refinement should be an iclass of the module.
    [ruby-core:83617] [Bug #14070]
    
    The superclass of a refinement should have BasicObject as its ancestor.
    
    Otherwise, VM_ASSERT(callable_method_entry_p(cme)) in
    prepare_callable_method_entry() fails if VM_CHECK_MODE is 2.

  Modified directories:
    branches/ruby_2_4/
  Modified files:
    branches/ruby_2_4/eval.c
    branches/ruby_2_4/test/ruby/test_refinement.rb
    branches/ruby_2_4/version.h