Rename syscall should replace target_path when it it exists

[Yesterday17]

wasmer/lib/wasi/src/syscalls/mod.rs

Lines 2662 to 2673 in 19e7e7a

	if state
	.fs
	.get_inode_at_path(
	inodes.deref_mut(),
	new_fd,
	target_path.to_str().as_ref().unwrap(),
	true,
	)
	.is_ok()
	{
	return Errno::Exist;
	}

If newpath already exists, it will be atomically replaced, so
that there is no point at which another process attempting to
access newpath will find it missing. However, there will
probably be a window in which both oldpath and newpath refer to
the file being renamed.

-- https://man7.org/linux/man-pages/man2/rename.2.html

[ptitSeb]

I checked the WASI spec, and indeed for path_rename there is

Rename a file or directory. Note: This is similar to renameat in POSIX.

So if the file exist, the file should be replace (atomicaly)

[syrusakbary]

This should be fixed by #3230