merge revision(s) 60182: [Backport #14009]
configure.ac: link Foundation framework * configure.ac (XLDFLAGS): link against Foundation framework and let __NSPlaceholderDictionary initialize, to get rid of crash after fork on macOS High Sierra. [ruby-core:83239] [Bug #14009]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@61358 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
merge revision(s) 60182: [Backport #14009]
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_4@61358 b2dd03c8-39d4-4d8f-98ff-823fe69b080e