Also, remove the possibility of passing in a compiler instance to
min_driver_version. This is because the NVCC compiler instance is,
as of CUDA Toolkit 11.0, no longer guaranteed to be versioned
identically to the toolkit itself.
D lang compilers have an option -release (or similar) which turns off
asserts, contracts, and other runtime type checking. This patch wires
that up to the b_ndebug flag.
Fixes#7082