RFR: 8292562: (fs) Use file cloning in Linux and macOS versions of Files::copy method [v9]

[Brian Burkhalter]

On Tue, 30 Aug 2022 00:23:46 GMT, Brian Burkhalter <bpb at openjdk.org> wrote:

>> Add file cloning to `java.nio.channels.FileChannel::transferTo` and `java.nio.file.Files.copy(Path,Path)`.
>
> Brian Burkhalter has updated the pull request with a new target base due to a merge or a rebase. The pull request now contains 13 commits:
> 
>  - 8264744: Refactor UnixCopyFile::copyFile into UnixFileSystem; refactor OS-specific code to {Bsd,Linux}FileSystem
>  - Merge
>  - 8264744: Add mode to clone() and other requested changes
>  - 8264744: Refactor {Bsd,Linux}CopyFile::clone into {Bsd,Linux}FileSystem::clone
>  - Merge
>  - 8264744: Remove CloneFile classes; refactor to use {Bsd,Linux}CopyFile
>  - Merge
>  - 8264744: Fix typo desintation -> destination
>  - 8264744: Refactor into UnixCopyFile hierarchy
>  - Merge
>  - ... and 3 more: https://git.openjdk.org/jdk/compare/c74b6d45...ecce2093

src/java.base/linux/native/libnio/fs/LinuxFileSystem.c line 96:

> 94:                     case EINVAL:
> 95:                     case EXDEV:
> 96:                         // ignore and try sendfile()

`ENOSYS` will need to be handled as done [here](https://github.com/openjdk/jdk/pull/10055/files#diff-4fdc393c9569db35d35d0b5698849aa939ba395ec5a685befadbb2bacbaddb3e).

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PR: https://git.openjdk.org/jdk/pull/9486