Do not throw from CUDAContext destructor (#34756)
Summary:
Throwing from destructor leads to undefined behaviour (most often to segault)
So it's better to leak memory then segault
Pull Request resolved: https://github.com/pytorch/pytorch/pull/34756
Test Plan: Run `test_pytorch_onnx_caffe2`
Differential Revision: D20504228
Pulled By: malfet
fbshipit-source-id: 7a05776fea9036f602e95b8182f8493cb5886dab
