Including `mbedtls/check_config.h` from `mbedtls/config.h` is optional. If
done, `limits.h` gets included. If not done, we were missing the inclusion
of `limits.h` in several source files. Fix this and add a test build that
doesn't include `mbedtls/check_config.h`.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
a8cd2e6421