tests/basics: Add tests for list and bytearray growing using themselves.

tests/basics/bytearray_slice_assign.py

@@ -51,6 +51,11 @@ b = bytearray(10)
 b[:-1] = bytearray(500)
 print(len(b), b[0], b[-1])
 
+# extension with self on RHS
+b = bytearray(x)
+b[4:] = b
+print(b)
+
 # Assignment of bytes to array slice
 b = bytearray(2)
 b[1:1] = b"12345"

tests/basics/list_slice_assign_grow.py

@@ -26,3 +26,8 @@ print(l)
 l = list(x)
 l[100:100] = [10, 20, 30, 40]
 print(l)
+
+# growing by using itself on RHS
+l = list(range(10))
+l[4:] = l
+print(l)