Make test_augassign pass with -Qnew and convert to unittest.

Lib/test/output/test_augassign

-test_augassign
-6
-[6]
-6
-[1, 2, 3, 4, 1, 2, 3, 4]
-[1, 2, 1, 2, 3]
-True
-True
-True
-11
-True
-12
-True
-True
-13
-__add__ called
-__radd__ called
-__iadd__ called
-__sub__ called
-__rsub__ called
-__isub__ called
-__mul__ called
-__rmul__ called
-__imul__ called
-__div__ called
-__rdiv__ called
-__idiv__ called
-__floordiv__ called
-__rfloordiv__ called
-__ifloordiv__ called
-__mod__ called
-__rmod__ called
-__imod__ called
-__pow__ called
-__rpow__ called
-__ipow__ called
-__or__ called
-__ror__ called
-__ior__ called
-__and__ called
-__rand__ called
-__iand__ called
-__xor__ called
-__rxor__ called
-__ixor__ called
-__rshift__ called
-__rrshift__ called
-__irshift__ called
-__lshift__ called
-__rlshift__ called
-__ilshift__ called