Umm...? The current project is the former UNI project, so you can very well build an ANSI version with that one, it was made for that purpose...
Personally, I think (and I may be wrong of course) that people using Windows 98 are rather a minority, and they know that they are using an outdated OS, and thus they have to expect (and are expecting) some drawback when it comes to new technologies. Unicode is one such issue, and gdb 6.3 is another.
I mean seriously, you (almost) cannot buy a PC without buying XP for several years now.
My point is that to make it half-way work for a few people, we have to add yet another hack for everybody. This means increased download size, possibly reduced stability, and increased load times for everybody.
So it may be worth a consideration if you maybe just have to accept that Windows98 and Unicode don't do together (at least not easily).