[clang] [Offload] Move HIP and CUDA to new driver by default (PR #84420)

[Joseph Huber via cfe-commits]

jhuber6 wrote:

> > > There are many `--no-offload-new-driver` test changes. They can be pre-committed to make this default flip modify fewer files.
> > 
> > 
> > I think it's much easier to keep these in a single patch, both for writing and with any potential reverting that it may require.
> 
> Since llvm is moving rapidly, reverting a commit that modifies many tests is quite risky, since these tests could have been modified by other changes or just cause merge conflicts for others. I assume that the merit of this patch is obvious (a new feature is in development for quite some time, then it matures and replaces the old feature), so adding `--no-offload-new-driver` (to mark "these tests are old, please update them when the new default has been stable for a while") is non-contentious. Pre-committing the test (which is not risky at all) would make this default flip patch much safer to land or revert.
> 
> If you think showing the difference is important, you can add to the description the test commits.

I'll try to pull out the files that are purely keeping the old behavior, since it'll be a no-op without this patch.

https://github.com/llvm/llvm-project/pull/84420