COMMITTED: Add support for STT_IFUNC

[Ian Lance Taylor]

Tristan Gingold <gingold@adacore.com> writes:

> I haven't look at the implementation, but is a STT_IFUNC allowed to
> have relocations
> against STT_IFUNC symbols ?
>
> If not, this is must be checked at link time, otherwise the entries
> must be topologically ordered.

I don't see why a topological ordering is required.  It suffices to
resolve the relocations lazily on demand.  Of course, a circular
reference will cause an error or an infinite loop.

Ian