emulators/spim: fix incorrect version comparisons, PR 57056 from "VMS"

It seems the lexer logic was checking the flex version with #if to
perform undocumented/unsupported frobs of the generated scanner's
internal state, but it had the version test wrong and so would have
been failing since flex's last minor version bump. The consequences
are apparently an infinite loop.

With the fix it no longer loops, but it still doesn't pass its own
very basic tests. It also uses its own builtin assembler (hence flex)
with nonstandard syntax (looks like also nonstandard semantics) and
who knows what else, so you're probably better off looking for a
different emulator.

(dholland)