Dunno if alpha is going to be the only glibc port to encounter this, if it should be considered a gcc bug, or what.
We get this because I chained aliases from __isnan to __isnanf to __GI___isnanf.
The patch works around this by defining both __isnanf and __GI___isnanf in terms of the original __isnan.
This isn't 100% correct since the __GI___isnanf symbol gets defined in the object file with visibility default, but it doesn't matter in practice because the users of the symbol still see the hidden_proto and so when the symbols are merged in the linker and link map applied, it acquires hidden visibility.
I'm looking for opinions as to whether (1) this is a gcc bug and (2) whether the patch should be applied to glibc regardless.
+	the original __isnan symbol.