Add numerical stability check

[WangDeyao]

Hi!

I accidentally pass tensor with inf and nan values into the torchsearchsorted. Instead of throwing, the function actually outputs some tensor value. The output tensor is a DISASTER. Any operations on the output tensor will cause the entire process frozen. (For example, print the output vector). Not even ctrl-c can break it. I have to quickly kill the process to avoid further damage to the machine.

It would be great if you can add a simple check before the computation. Terminate the code if it finds there are nan or inf value exists.

Thanks!