[External][CUDA] Add option to test with the new driver

Upstream clang supports RDC-mode compilation through the new driver.
This patch adds an option that allows the user to configure the compilation
job to use the new driver for testing. This will allow us to optionally test the
new driver in the buildbots to track changes as we develop.

Reviewed By: tra

Differential Revision: https://reviews.llvm.org/D126231
1 file changed