GitLab

Instead of replacing all #ifdef USE_CUDA, just add USE_CUDA define to ROCm build.

Previously #6086 added ROCm support but after numerous rebases it lost
critical changes. This PR restores the ROCm build.

There are many source file changes but most were automated using the
following:

```bash
for f in `grep -rl '#ifdef USE_CUDA'`
do
    sed -i 's@#ifdef USE_CUDA@#if defined(USE_CUDA) || defined(USE_ROCM)@g' $f
done

for f in `grep -rl '#endif  // USE_CUDA'`
do
    sed -i 's@#endif  // USE_CUDA@#endif  // USE_CUDA || USE_ROCM@g' $f
done
```

* [ci] speed up if-else, swig, and lint conda setup

* add 'source activate'

* python constraint

* start removing cuda v1

* comment out CI

* remove more references

* revert some unnecessaary changes

* revert a few more mistakes

* revert another change that ignored params

* sigh

* remove CUDATreeLearner

* fix tests, docs

* fix quoting in setup.py

* restore all CI

* Apply suggestions from code review
Co-authored-by: shiyu1994 <shiyu_k1994@qq.com>

* Apply suggestions from code review

* completely remove cuda_exp, update docs

---------
Co-authored-by: shiyu1994 <shiyu_k1994@qq.com>

* add rmse metric for new cuda version

* add Init for CUDAMetricInterface

* fix lint errors

[CUDA] Add Poisson regression objective for cuda_exp and refactor objective functions for cuda_exp (#5486)

* add poisson regression objective for cuda_exp

* enable Poisson regression for cuda_exp

* refactor cuda objective functions

* remove useless changes

* fix linter errors

* remove redundant buffer in cuda poisson regression objective

* fix log of cuda_exp binary objective

* fix threshold of poisson objective result

* remove useless changes

* fix compilation errors

* add cuda quantile regression objective

* remove cuda quantile regression objective
Co-authored-by: James Lamb <jaylamb20@gmail.com>

* add multiclass objective for cuda_exp

* remove debug code

* add includes requested by lint checks

* fix compilation failure for cuda with cuda-9.0

* clean code