LightGBM

[python] Windows wheels that support GPUs via OpenCL (#3403)

* Add specialized OpenCL/Python package build path

* Refer to upstream OpenCL repository

* Reset build job count in setup.py

* Run test for dual CPU/GPU code in CI

* TEMPORARY: refer to OpenCL fork to ensure Linux CI builds succeed

* Try switching to OpenCL 2.0

* Add --opencl-python-pacakge option to wheel

* Fix some typos.

* Remove intermediate cmake target

* Restrict OpenCL headers to documented API version

* Refresh the environment after installation

* Try testing with two processes

* Use command line definition to activate integrated build

* Try newer OpenCL runtime

* If we hit OpenCL code path that's good enough

* Make tests run correctly

* Correct directory

* Flag reference to unofficial repo with FIXME

* TEMPORARY: update private repo tag for dependency

* Further post-merge fixes.

* Fix attribute name.

* Reformat with black.

* Rewrite config.h before library compilation for Windows wheel

* Run dual cpu/gpu test once only for Windows bdist CI

* Avoid C API tests when building gpu library for wheel

* TEMPORARY -- add clinfo tool to vm for debugging

* Increase compilation logging

* Rename OpenCL registry parameter after driver installation

* Install legacy OpenCL runtime

* ...

* Remove config.h change, clinfo installation, latest opencl runtime reference

* Add explicit script exit

* revert to 18.1 intel driver

* Run test_dual.py in two different modes

* Revert "Run test_dual.py in two different modes"

This reverts commit cbfec02659816f0cb321e1184994a9c2f37d2a77.

* Remove unused expected failure test

* Install OpenCL in separate powershell script

* fix setup.py imports

* activate conda env after session update

* separate update functions; exit opencl installation on error

* nothing; start pipeline

* download from original source

* specify tls version for installer download

* eliminate variable from command

* download opencl installer in parts

* remove duplicate setup.py command class entry

* download smaller parts

* remove redundant bdist wheel class

* Import chocolatey modules and use RefreshEnv

* insert pipeline cache for opencl installer

* rerun to ensure pipeline cache hit

* add comments, test another pipeline cache hit

* remove cache task; download full installer file from new location

* try another installer download timing

* reinsert pipeline cache

* retain cache task; download full file on cache miss

* test cache hit again

* remove todo

Co-authored-by: TP Boudreau <tpboudreau@gmail.com>