kwsys: add a clonefile optimization for Darwin
Implement the copy file optimization on Darwin for copy_file
and
copy_file_if_different
. Use the new clonefile
API on macOS 10.12 or
newer to CoW the file instead of using a block copy.
Implement the copy file optimization on Darwin for copy_file
and
copy_file_if_different
. Use the new clonefile
API on macOS 10.12 or
newer to CoW the file instead of using a block copy.