test: add windows-only snprintf() function
test: add windows-only snprintf() function

Should fix the build after 96f32a2 inadvertently broke it.

There is no snprintf() on Windows because, hey, it's a C99 addition
and the people from Redmond, WA are still firmly stuck in 1989.

unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso,unknownbrackets/maxcso