After rL289878/rL289881, the build on FreeBSD is broken, because
sanitizer_platform_limits_posix.cc attempts to include <utmp.h> and use
struct utmp, neither of which are supported anymore on FreeBSD.
Fix this by adding && !SANITIZER_FREEBSD in two places.
If there is no getutent, you probably want to disable the interceptor in sanitizer_platform_interceptors.h.
Add an ifdef around the declaration of struct_utmp_sz as well.
Updated to cover some more cases:
I'm the author of FreeBSD's utmpx. LGTM!