* Use cuda virtual memory management and merge blocks, test=develop

* refine, test=develop

* refine, test=develop

* refine, test=develop

* refine, test=develop

* refine, test=develop

* refine, test=develop

* refine, test=develop

* window dll, test=develop

* fix cuda error of CUDA_ERROR_NOT_INITIALIZED, test=develop

* use autogrowthv2 for system allocator, test=develop

* remove ~CUDAVirtualMemAllocator(), test=develop

* refine, test=develop

* fix cuda error of CUDA_ERROR_NOT_INITIALIZED, test=develop

* fix cuda error of CUDA_ERROR_NOT_INITIALIZED, test=develop

* fix bug, test=develop

* revert system allocator, test =develop

* revert multiprocessing, test=develop

* fix AutoGrowthBestFitAllocatorV2 mutxt, test=develop

* catch cudaErrorInitializationError when create allocator, test=develop

* fix cuMemSetAccess use, test=develop

* refine cuda api use, test=develop

* refine, test=develop

* for test, test=develop

* for test, test=develop

* switch to v2, test=develop

* refine virtual allocator, test=develop

* Record cuMemCreate and cuMemRelease, test=develop

* refine, test=develop

* avoid out of bounds, test=develop

* rename allocator, test=develop

* refine, test=develop

* use PADDLE_ENFORCE_CUDA_SUCCESS, test=develop

* for test,test=develop

* refine, test=develop

* refine, test=develop

* refine, test=develop

* refine, test=develop

* refine, test=develop

* refine, test=develop

* use iwyu clean include, test=develop, test=win

* compilation error, test=develop

* fix compilation error2, test=develop

* fix compilation error3, test=develop

* fix compilation error4, test=develop

* fix compilation error5, test=develop

* fix compilation error6, test=develop

* fix compilation error7, test=develop

* fix compilation error8, test=develop

* fix compilation error8, test=develop

* fix compilation error10, test=develop

* fix compilation error11, test=develop

* Add the check for whether CUDA Driver and NVRTC is available for the runtime system.

* Call cuInit to initialize the CUDA Driver API before all CUDA callings.
test=develop

* Change the behavior when libnvrtc.so can not be found, printing a warning instead of exiting.
test=develop

* Do not initialize CUDA Driver API for windows and macos.
test=develop

* Remove the call of cuInit when entering paddle and enable the test_code_generator.
test=develop

* Add some built-in functions for __half.
test=develop

* Change save_intermediate_out to false in unittest.
test=develop

* Fix error reference to tempropary variable when seting including path for device_code.
test=develop

* Add the dynamic load of nvrtc, and support runtime compiling of CUDA kernel using nvrtc.
test=develop

* Call CUDA driver api to launch the kernel compiled by nvrtc.
test=develop

* Disable for mac and windows.
test=develop

* Refine the codes to support manually specified num_threads and workload_per_thread.
test=develop

* Refine the CUDA kernel to support large dims.
test=develop

* Add DeviceCodePool to manage all device codes.

* Add the first implementation fusion_group op.

* Add unit-test for fusion_group op.

* Add the check of result.

* Add the check of nvrtc in unit-test.
test=develop

* Add comment to explain the inputs, outputs and features of fusion_group op.
test=develop

* Disable fusion_group op for mac and windows.
test=develop

* Make the compiling of device code return status instead of hanging up.
test=develop

* Add the check of whether there is CUDA driver library, and do not core dump when failing to call the CUDA driver API.

* Unify fusion_group_op's input and output names.
test=develop

* Add the check of CUDA driver library in unittest.
test=develop

* Refine the calling of PADDLE_ENFORCE.
test=develop

* Add the dynamic load of nvrtc, and support runtime compiling of CUDA kernel using nvrtc.
test=develop

* Call CUDA driver api to launch the kernel compiled by nvrtc.
test=develop

* Disable for mac and windows.
test=develop

* Refine the codes to support manually specified num_threads and workload_per_thread.
test=develop

* Refine the CUDA kernel to support large dims.
test=develop