I'd argue that in good old C, #defines for pure constants are pretty well established and considered idiomatic. In other words, I wouldn't ding it in a code review. (Nor would I ding the enum solution. Either one is perfectly cromulent.) In some ways, even though we now have better alternatives in C, I kinda feel like any C tool and any C programmer had better be able to deal with #define constants. Quickly browsing the vim source, it looks like they have seem to default to using #define for constants, and "when in Rome" is a good rule of thumb to live by. :)

On the other hand, I'm really a C++ guy, and in that domain, I'd prefer your "const uint32_t" solution. It just feels more idiomatic.

Additionally and somewhat pedantically, I prefer naming conventions that make it clear when values are a constant, so I'd use "kHebrewCharMin" or something simliar.