get_cuda_lib_handle brought back so import works

bitsandbytes/cuda_setup/main.py

@@ -360,3 +360,13 @@ def evaluate_cuda_setup():
         binary_name = f"libbitsandbytes_cuda{cuda_version_string}_nocublaslt.so"
 
     return binary_name, cudart_path, cc, cuda_version_string
+
+def get_cuda_lib_handle():
+    # 1. find libcuda.so library (GPU driver) (/usr/lib)
+    try:
+        cuda = ct.CDLL("libcuda.so")
+    except OSError:
+        CUDASetup.get_instance().add_log_entry('CUDA SETUP: WARNING! libcuda.so not found! Do you have a CUDA driver installed? If you are on a cluster, make sure you are on a CUDA machine!')
+        return None
+
+    return cuda
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