[trans-mem] mark _ITM_cxa_throw and _ITM_cxa_allocate_exception as pure

[Aldy Hernandez]

On 12/13/10 16:20, Aldy Hernandez wrote:
> Both of these are handled by the runtime, and should be TM pure.  
> Otherwise throwing won't work, even with our fancy 
> _ITM_cxa_throw/_ITM_cxa_allocate_exception functions.
>
> OK for branch?
>
rth approved off-list with the exception of the library bits.

Committing.