Implement -samefile

[hanbings]

No description provided.

[github-actions]

Commit a523add has GNU testsuite comparison:

Run GNU findutils tests: early EOF
Run GNU findutils tests: fetch-pack: invalid index-pack output
Run GNU findutils tests: RPC failed; curl 56 GnuTLS recv error (-9): Error decoding the received TLS packet.
Run GNU findutils tests: 4096 bytes of body are still expected
Run GNU findutils tests: Congrats! The GNU test samefile-copy.new-O0 is now passing!
Run GNU findutils tests: Congrats! The GNU test samefile-copy.new-O1 is now passing!
Run GNU findutils tests: Congrats! The GNU test samefile-copy.new-O2 is now passing!
Run GNU findutils tests: Congrats! The GNU test samefile-copy.new-O3 is now passing!
Run GNU findutils tests: Congrats! The GNU test samefile-link.new-O0 is now passing!
Run GNU findutils tests: Congrats! The GNU test samefile-link.new-O1 is now passing!
Run GNU findutils tests: Congrats! The GNU test samefile-link.new-O2 is now passing!
Run GNU findutils tests: GNU tests summary = TOTAL: 706 / PASS: 441 / FAIL: 262 / ERROR: 2
Run GNU findutils tests: Changes from main: PASS +8 / FAIL -20 / ERROR +0 / SKIP +0 
Run BFS tests: Changes from main: PASS +0 / SKIP +0 / FAIL +0
Run BFS tests: BFS tests No changes
Run BFS tests: BFS tests summary = TOTAL: 288 / PASS: 184 / SKIP: 1 / FAIL: 103