tests/basics/list_slice_3arg: Add more tests for negative slicing.

Author: dpgeorge

tests/basics/list_slice_3arg.py

@@ -26,3 +26,14 @@
 print(x[-1:-2:-1])
 print(x[-1:-11:-1])
 print(x[-10:-11:-1])
+print(x[:-15:-1])
+
+# test negative indices that are out-of-bounds
+print([][::-1])
+print([1][::-1])
+print([][0:-10:-1])
+print([1][0:-10:-1])
+print([][:-20:-1])
+print([1][:-20:-1])
+print([][-20::-1])
+print([1][-20::-1])