Clean up CUDA state between tests (#2335)

This PR fixes the unit test,

test/test_cuda.py::TestCuda::test_set_per_process_memory_fraction FAILED
[0.1163s]

```
Traceback (most recent call last):
  File "/var/lib/jenkins/pytorch/test/test_cuda.py", line 471, in test_set_per_process_memory_fraction
    tmp_tensor = torch.empty(application, dtype=torch.int8, device="cuda")
RuntimeError: Trying to create tensor with negative dimension -5681285432: [-5681285432]
```
This error occurs only on gfx1101 arch.

This error is coming from an integer overflow when another unit test,
test/test_cuda.py::TestCuda::test_randint_generation_for_large_numel
creates a tensor with a huge numel, which overflows into a higher
torch.cuda.max_memory_reserved() when you call
test/test_cuda.py::TestCuda::test_set_per_process_memory_fraction
afterward. To avoid this we introduced torch.cuda.empty_cache() and
torch.cuda.reset_peak_memory_stats() to clean up CUDA states.

JIRA: https://ontrack-internal.amd.com/browse/SWDEV-535295
(cherry picked from commit f86d184)
(cherry picked from commit 1b44228)

Author: rraminen

test/test_cuda.py

@@ -504,6 +504,9 @@ def test_out_of_memory_retry(self):
         IS_JETSON, "oom reporting has issues on jetson igx due to partial nvml support"
     )
     def test_set_per_process_memory_fraction(self):
+        if torch.version.hip and ('gfx1101' in torch.cuda.get_device_properties(0).gcnArchName):
+           torch.cuda.empty_cache()
+           torch.cuda.reset_peak_memory_stats()
         orig = torch.cuda.get_per_process_memory_fraction(0)
         torch.cuda.reset_peak_memory_stats(0)
         try: