Say we also implement librt.so.1. This is required, for example, by the
Boost libraries (e.g., libboost_system-mt.so.1.50.0). The librt library
isn't actually a separate library on modern Linux - rather all its
traditional functions are now in glibc, and "librt" is merely a filter
on glibc. So no reason not to say we support librt too.

Not to mention that we already implement a bunch of functions that
traditionally resided in librt (nanosleep, sched_yield, sem_*, etc.