* signal.c: need to include unistd.h for write(2).
  unistd.h is now included via ruby/defines.h, but should implicitly
  include here.  (suggested by kosaki)


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40743 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
* 2013-05-15

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@40744 b2dd03c8-39d4-4d8f-98ff-823fe69b080e