PATCH: R600: Fix handling of kernel arguments

[Tom Stellard]

Hi,

The attached patches fix various bugs in the handling of kernel arguments
in the R600 backend.  The main problem with the old implementations was
that it disagreed with clover on type size and alignment, so vector
arguments were not being loaded correctly into the kernel.

This series depends on this patch:

http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20131014/191252.html

Please review and test.

-Tom