dirDeleteFileWasi

fn dirDeleteFileWasi(userdata: ?*anyopaque, dir: Dir, sub_path: []const u8) Dir.DeleteFileError!void {
    if (builtin.link_libc) return dirDeleteFilePosix(userdata, dir, sub_path);
    const t: *Threaded = @ptrCast(@alignCast(userdata));
    _ = t;
    const wasi = std.os.wasi;
    const syscall: Syscall = try .start();
    while (true) {
        const res = wasi.path_unlink_file(dir.handle, sub_path.ptr, sub_path.len);
        switch (res) {
            .SUCCESS => {
                syscall.finish();
                return;
            },
            .INTR => {
                try syscall.checkCancel();
                continue;
            },
            .ACCES, .PERM => |e| {
                const original_error: Dir.DeleteFileError = switch (e) {
                    .ACCES => error.AccessDenied,
                    .PERM => error.PermissionDenied,
                    else => unreachable,
                };
                var stat: wasi.filestat_t = undefined;
                while (true) {
                    try syscall.checkCancel();
                    switch (wasi.path_filestat_get(dir.handle, .{}, sub_path.ptr, sub_path.len, &stat)) {
                        .SUCCESS => {
                            syscall.finish();
                            break;
                        },
                        .INTR => continue,
                        else => {
                            syscall.finish();
                            return original_error;
                        },
                    }
                }
                if (stat.filetype == .DIRECTORY)
                    return error.IsDir
                else
                    return original_error;
            },
            else => |e| {
                syscall.finish();
                switch (e) {
                    .BUSY => return error.FileBusy,
                    .FAULT => |err| return errnoBug(err),
                    .IO => return error.FileSystem,
                    .ISDIR => return error.IsDir,
                    .LOOP => return error.SymLinkLoop,
                    .NAMETOOLONG => return error.NameTooLong,
                    .NOENT => return error.FileNotFound,
                    .NOTDIR => return error.NotDir,
                    .NOMEM => return error.SystemResources,
                    .ROFS => return error.ReadOnlyFileSystem,
                    .NOTCAPABLE => return error.AccessDenied,
                    .ILSEQ => return error.BadPathName,
                    .INVAL => |err| return errnoBug(err), // invalid flags, or pathname has . as last component
                    .BADF => |err| return errnoBug(err), // File descriptor used after closed.
                    else => |err| return posix.unexpectedErrno(err),
                }
            },
        }
    }
}