process.c: default process encoding
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41701 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
process.c: default process encoding
encoding if defined.
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41701 b2dd03c8-39d4-4d8f-98ff-823fe69b080e