moved spmv to c++. Required for dummy visc calls

llvm/test/VISC/parboil/benchmarks/spmv/src/visc/Makefile

llvm/test/VISC/parboil/benchmarks/spmv/src/visc/file.cpp

llvm/test/VISC/parboil/benchmarks/spmv/src/visc/gpu_info.cpp

llvm/test/VISC/parboil/benchmarks/spmv/src/visc/main.cpp