We aim to produce code that works with C90 or C++98 so we can't
assume snprintf() is available, but it almost always is (even
on systems from before it was standardised) so having a way to
use it is helpful.
Enable this automatically if the compiler claims conformance
with at least C90 or C++98 and check SWIG_HAVE_SNPRINTF to allow
turning on manually, but disable if SWIG_NO_SNPRINTF if defined.
The fallback is to call sprintf() without a buffer size check -
checking after the call is really shutting the stable door after
the horse has bolted, and most of our uses either have a fixed maximum
possible size or dynamically allocate a buffer that's large enough.
Fixes: #2502 (sprintf deprecation warnings on macos)
Fixes: #2548
1f5ff2e6a5