[ruby-cvs:66400] usa:r59222 (ruby_2_3): merge revision(s) 53400: [Backport #13572]

[usa at ruby-lang.org]

usa	2017-06-30 19:58:32 +0900 (Fri, 30 Jun 2017)

  New Revision: 59222

  https://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=revision&revision=59222

  Log:
    merge revision(s) 53400: [Backport #13572]
    
    * tool/mkconfig.rb (RbConfig): prefix SDKROOT to oldincludedir
      not includedir, the latter is outside the ruby installation.
      [ruby-core:72496] [Bug #11881]

  Modified directories:
    branches/ruby_2_3/
  Modified files:
    branches/ruby_2_3/ChangeLog
    branches/ruby_2_3/tool/mkconfig.rb
    branches/ruby_2_3/version.h