Fix get_chunks for zeros

sdc/tests/test_prange_utils.py

@@ -68,6 +68,8 @@ def _get_chunks_data(self):
             Chunk(start=3, stop=6),
             Chunk(start=6, stop=9),
         ]
+        yield (0, 5), []
+        yield (5, 0), []
 
     def _check_get_chunks(self, args, expected_chunks):
         pyfunc = get_chunks

sdc/utilities/prange_utils.py

@@ -47,11 +47,15 @@ def get_pool_size():
 
 @sdc_register_jitable
 def get_chunks(size, pool_size):
+    chunks = []
+
+    if size < 1 or pool_size < 1:
+        return chunks
+
     pool_size = min(pool_size, size)
     chunk_size = size // pool_size
     overload_size = size % pool_size
 
-    chunks = []
     for i in range(pool_size):
         start = i * chunk_size + min(i, overload_size)
         stop = (i + 1) * chunk_size + min(i + 1, overload_size)