quantized_tensor tests (#26784)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/26784
Previously we are using empty to generate test tensors, this PR changes the test tensors to use
randint so that we can test things properly
Also added a set_sizes_and_strides and removed .contiguous() in int_repr function to preserve the
original size and strides
Test Plan:
python test/test_quantized_tensor.py
Imported from OSS
Differential Revision: D17566575
fbshipit-source-id: 89379fb09b500dd156118e6ee0709df59f169990
