Why ar doesn't call ranlib on Mac?

[Alexy Khrabrov]

In building various Linux things from source on Mac, I've run into the  
"archive has no table of contents" problem several times.  The fix is  
invariably to go and stick ranlib after each ar.

Now I wonder, why don't we replace /usr/bin/ar with a wrapper calling  
the ar and then ranlib if it's an ar c?  No more stupid ranlib  
peppering then!

And what's wrong with Macs anyways?  Why do we have to do it where  
Linux folks are happy without it?

Cheers,
Alexy