I’m not even sure if it is possible to display multiple glyph-languages at the same time. Many fonts have language specific versions, eg: Droid Sans, Droid Sans Arabic, Droid Sans Hebrew, Droid Sans Thai.
As well I don’t believe I’ve seen an editor of any type that can load multiple fonts at the same time (on the fly) in order to display disparate characters. Notepad++ I believe can use different fonts at the same time for Syntax-Highlight but that’s an entirely different matter.