reaply r48278

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48298 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
make-snapshot: HAVE_BASERUBY

* tool/make-snapshot: set HAVE_BASERUBY to download Unicode data
  files.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48299 b2dd03c8-39d4-4d8f-98ff-823fe69b080e