Memory pooling issue in HIP adapter

[igchor]

HIP adapter has an ifdef to enable pooling support in urUSMPoolCreate:

unified-runtime/source/adapters/hip/usm.cpp

Line 388 in 4aeb55e

#ifdef UMF_ENABLE_POOL_TRACKING

The define, however is never set which means we do not test HIP with pooling enabled at all.

I tried setting UMF_ENABLE_POOL_TRACKING but this results in segfault in tests:

# ./bin/test-sum

...

[----------] 12 tests from urUSMHostAllocTest
[ RUN      ] urUSMHostAllocTest.Success/AMD_HIP_BACKEND___AMD_Radeon_RX_6800_XT___UsePoolEnabled
Segmentation fault (core dumped)