Link devicelib during device code compilation

[MartinWehking]

Note: This patch is based on 15048 (Not merged yet) and links against the final resulting bitcode library that is created through that patch

Use the -mlink-builtin-bitcode flag to link the CUDA devicelib during device code compilation instead of generating a separate llvm-link action in the driver.

Add a new flag to exclude linking of libdevice completely.

Add a new error in case that the cuda devicelib file can not be found.