Fix bug of indexing with ellipsis(...)

[zyfncg]

PR types

Bug fixes

PR changes

APIs

Describe

修复了一维Tensor在使用省略号(...)索引时维度检测异常的问题。

Exmple:

Before this PR:

>>> x = paddle.to_tensor([1, 2, 3, 4])
>>> print(x[..., 0])
#  ValueError: (InvalidArgument) Too many indices (2) for tensor of dimension 1.
#  [Hint: Expected valid_indexs <= rank == true, but received valid_indexs <= rank:0 != true:1.]

Now:

>>> x = paddle.to_tensor([1, 2, 3, 4])
>>> print(x[..., 0])
# Tensor(shape=[1], dtype=int64, place=CUDAPlace(0), stop_gradient=True, 
#              [1])

[paddle-bot-old]

Thanks for your contribution!
Please wait for the result of CI firstly. See Paddle CI Manual for details.

[chenwhql]

LGTM