R600: Add v2i32 test for vselect

Note: Only adding test for evergreen, not SI yet.

When I attempted to expand vselect for SI, I got the following:
llc: /home/awatry/src/llvm/lib/CodeGen/SelectionDAG/LegalizeIntegerTypes.cpp:522:
llvm::SDValue llvm::DAGTypeLegalizer::PromoteIntRes_SETCC(llvm::SDNode*):
Assertion `SVT.isVector() == N->getOperand(0).getValueType().isVector() &&
"Vector compare must return a vector result!"' failed.

Reviewed-by: Tom Stellard <thomas.stellard@amd.com>
llvm-svn: 184847