Node: Support UV_FS_COPYFILE_FICLONE

[langpavel]

UV_FS_COPYFILE_FICLONE was just merged to libuv: unix: add UV_FS_COPYFILE_FICLONE support

When will be this merged into node? Will this be backported to node 8?

[cjihrig]

I'll be adding support for it when the next libuv update is merged. My guess is that it will be backported to Node 8, as most of the work happens in libuv.

[langpavel]

Relevant paragraph from libuv docs:

.. c:function:: int uv_fs_copyfile(uv_loop_t* loop, uv_fs_t* req, const char* path, const char* new_path, int flags, uv_fs_cb cb)
Copies a file from path to new_path. Supported flags are described below.
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- UV_FS_COPYFILE_FICLONE: If present, uv_fs_copyfile() will attempt to
create a copy-on-write reflink. If the underlying platform does not
support copy-on-write, then a fallback copy mechanism is used.
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.. versionchanged:: 1.20.0 UV_FS_COPYFILE_FICLONE is supported.