Fix bug in VISUAL_STUDIO_SAFEINT_COMPAT define
The VISUAL_STUDIO_SAFEINT_COMPAT is to manage a very old issue to help people who were using the Visual Studio version of SafeInt migrate to this version, which is supported. There was a bug where if SafeInt were multiply included, and this define was set, it wouldn't compile.
The VISUAL_STUDIO_SAFEINT_COMPAT define will be removed in a future release.