Add midding hipStream SWIG typedef to fix ROCm memleak in Python (facebookresearch#3760)

Summary:
Pull Request resolved: facebookresearch#3760

This fixes the memleak and the warning received after running Python tests under ROCm since no destructor was declared and objects would remain allocated.

Reviewed By: gtwang01

Differential Revision: D61357579

fbshipit-source-id: cf73bbd7a7002565a4224c1f0af0aa6ea5edebdb

Author: ramilbakhshyiev

faiss/python/swigfaiss.swig

@@ -352,6 +352,8 @@ void gpu_sync_all_devices()
 %include  <faiss/gpu-rocm/GpuResources.h>
 %include  <faiss/gpu-rocm/StandardGpuResources.h>
 
+typedef ihipStream_t* hipStream_t;
+
 %inline %{
 
 // interop between pytorch exposed hipStream_t and faiss