Seemingly, names in anonymous namespaces are ALWAYS given the unique
internal linkage name on windows, and I was not aware of this when I put
the names in my test! Replaced them with a wildcard.
We previously made all multiversioning resolvers/ifuncs have weak
ODR linkage in IR, since we NEED to emit the whole resolver every time
we see a call, but it is not necessarily the place where all the
definitions live.
HOWEVER, when doing so, we neglected the case where the versions have
internal linkage. This patch ensures we do this, so you don't get weird
behavior with static functions.