DMD-MAC!!

[Walter Bright]

Sean Kelly wrote:
> There are pthread calls for TLS which are implemented for OSX.  But 
> however it works (I haven't looked into it), it likely isn't as 
> efficient or easy to deal with as the __thread storage class on other OSes.

It won't be as efficient. But that really doesn't matter at this point - 
accessing global variables in a tight loop is a bad idea anyway. TLS 
just has to work. It can be optimized later as OSX improves (which it 
must, as TLS is going to be a bigger and bigger deal as time goes on).