Check if sufficient GPUs are available

The CUDA error message "Test CUDA failure util.cu:706 'invalid device ordinal'"
is not as helpful. Test this explicitly and guide the user.

Fix compilation for old NCCL versions

Fix compilation failure on ctaPolicy with NCCL <= 2.26.
Fix compilation failure on local_register with NCCL <= 2.18.
Fix ctaPolicy behavior if the tests are compiled with NCCL <= 2.26
but run with NCCL >= 2.27.

Update to align with the NCCL 2.28 release

Added Device API infrastructure and example kernels
Two new command line arguments:

  -D <num> device kernel implementation to use <0/1/2/3/4>
  -V <num> number of CTAs to launch device kernels with

Added new CTA Policy command line option:

  -x <policy> set the CTA Policy <0/1/2>

Update NVCUFLAGS and CXXFLAGS to use -std=c++14

Modified warmup to run for more message sizes

Loops between minBytes and maxBytes doubling size each time

Reduced default warmup iteration count to 1 (was 5)

Merge pull request #316 from martin-belanger/print-program-name

Print the name of the program being executed before and after test output

Add extra reserved space during maxBytes calculation

Also, don't allow minBytes > maxBytes

Minor fix to Makefile

Move comments to separate lines

Add Turing (SM75) support to CUDA 13.0 builds

Wrap ncclCommWindowRegister() calls within ncclGroup