Use the eventually true UNICODE imageNameT if -DUNICODE
Use the eventually true UNICODE imageNameT if -DUNICODE

using `toUnicode` does not do the right thing: it promotes each UTF8 byte code to short...
... which can hardly work beyond ASCII.

OpenSmalltalk/vm,timfel/squeakvm,OpenSmalltalk/vm,timfel/squeakvm,timfel/squeakvm,timfel/squeakvm,timfel/squeakvm,OpenSmalltalk/vm,timfel/squeakvm,timfel/squeakvm,OpenSmalltalk/vm,OpenSmalltalk/vm,timfel/squeakvm,OpenSmalltalk/vm,OpenSmalltalk/vm,OpenSmalltalk/vm