Added more verbose error reporting
Removed debugging printf
Working vector add test.

Note 1: To run the tests, the file <pocl-build>/lib/kernel/nvptx64/kernel-nvptx64-nvidia-cuda.bc must include the get_global_id function. Currenlty using a handcompiled version of libclc (http://libclc.llvm.org/).
Build instructions:
After building libclc run the following command in the folder nvptx64--nvidiacl/lib/workitem

llvm-link get_global_id.cl.bc get_global_size.cl.bc get_group_id.cl.bc get_local_id.cl.bc get_local_size.cl.bc get_num_groups.cl.bc  -o kernel-nvptx64--nvidiacl.bc
llvm-dis kernel-nvptx64--nvidiacl.bc
sed 's/nvptx64--nvidiacl/nvptx64-nvidia-cuda/' kernel-nvptx64--nvidiacl.ll >kernel-nvptx64-nvidia-cuda.ll
sed -i 's/get_global_id/_Z13get_global_idj/' kernel-nvptx64-nvidia-cuda.ll
llvm-as kernel-nvptx64-nvidia-cuda.ll

mkdir -p <pocl-build>/lib/kernel/nvptx64
cp kernel-nvptx64-nvidia-cuda.ll <pocl-build>/lib/kernel/nvptx64/kernel-nvptx64-nvidia-cuda.bc

Note 2: As you can see from the second `sed` command the function name, get_global_id, must be changed inorder for this to work.