Refactor _reg_maths* and _reg_common_cuda_kernels #120

	name: Coverage
	on: [push, pull_request]
	jobs:
	Coverage:
	runs-on: [self-hosted, linux, gpu]
	steps:
	- uses: actions/checkout@v3

	- name: Install dependencies
	run: sudo apt-get update && sudo apt-get install -y cmake git lcov

	- name: Install Catch2
	run: \|
	git clone https://github.com/catchorg/Catch2.git
	cd Catch2
	cmake -Bbuild -H. -DBUILD_TESTING=OFF
	sudo cmake --build build/ --target install --config Debug

	- name: Configure NiftyReg
	run: \|
	mkdir build
	cd build
	cmake -DCMAKE_C_COMPILER=gcc \
	-DCMAKE_CXX_COMPILER=g++ \
	-DCMAKE_BUILD_TYPE=Debug \
	-DBUILD_ALL_DEP=ON \
	-DUSE_CUDA=ON \
	-DUSE_OPENCL=OFF \
	-DUSE_SSE=OFF \
	-DUSE_OPENMP=OFF \
	-DBUILD_TESTING=ON \
	-DWITH_COVERAGE=ON \
	..

	- name: Build NiftyReg
	run: cmake --build build --config Debug

	- name: Run tests
	working-directory: build
	run: ctest -V

	- name: Coverage
	working-directory: build
	run: make coverage

	- name: Upload coverage to Codecov
	uses: codecov/codecov-action@v3
	with:
	directory: build
	env:
	CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}

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