[ruby-cvs:63090] usa:r55925 (ruby_2_2): merge revision(s) 55729: [Backport #12611]

[usa at ruby-lang.org]

usa	2016-08-16 13:56:04 +0900 (Tue, 16 Aug 2016)

  New Revision: 55925

  https://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=revision&revision=55925

  Log:
    merge revision(s) 55729: [Backport #12611]
    
    * vm.c (vm_set_main_stack): remove unnecessary check.  toplevel
      binding must be initialized.  [Bug #12611] (N1)
    
    * win32/win32.c (w32_symlink): fix return type.  [Bug #12611] (N3)
    
    * string.c (rb_str_split_m): simplify the condition.
      [Bug #12611](N4)

  Modified directories:
    branches/ruby_2_2/
  Modified files:
    branches/ruby_2_2/ChangeLog
    branches/ruby_2_2/string.c
    branches/ruby_2_2/version.h
    branches/ruby_2_2/vm.c