PATCH: Add getVectorIdxTy() function to TargetLowering

[Tom Stellard]

On Fri, Jul 19, 2013 at 01:14:30PM -0700, Tom Stellard wrote:
> Hi,
> 
> The attached patch adds the virtual function getVectorIdxTy() to the
> TargetLowering class.  There are two motivations for this new function,
> the first is to clean up some bad code that is generated when using
> dynamic indexing of vectors in the R600 target.  The second is to reduce
> the use of TargetLowering::getPointerTy() in the SelectionDAG code which
> will help anyone who is trying to improve support for targets whose
> pointer size differs across address spaces.
> 

Nadav suggested on IRC that I use the MVT::i32 type everywhere rather
than adding a callback to TargetLowering.  I will submit a new patch
shortly.

-Tom