[ruby-cvs:61568] naruse:r54406 (ruby_2_3): merge revision(s) 53868: [Backport #12071]

[naruse at ruby-lang.org]

naruse	2016-03-29 23:36:52 +0900 (Tue, 29 Mar 2016)

  New Revision: 54406

  https://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=revision&revision=54406

  Log:
    merge revision(s) 53868: [Backport #12071]
    
    * ext/extmk.rb: add cygwin case, nothing excluded.
      [ruby-core:73806] [Bug#12071]

  Modified directories:
    branches/ruby_2_3/
  Modified files:
    branches/ruby_2_3/ChangeLog
    branches/ruby_2_3/ext/extmk.rb
    branches/ruby_2_3/version.h