[MLton] powerpc, getrusage problem again?

[Matthew Fluet]

> I reported earlier that MLton was calling getrusage alot.
> This had something to do with HAS_WEAK?
> 
> Well, the problem still appears on powerpc, but not i386.
> So, I am guessing that for some reason powerpc has no
> weak pointers? That's a shame as I was planning on using
> them there.

HAS_WEAK has nothing to do with MLton's weak pointers.  It has to do with 
the gcc weak attribute, which allows you to reference a symbol without 
causing an unbound symbol linking error should the symbol not be 
(non-weakly) referenced by something else.