These helper function implementations were introduced in 3.0.2 in the sysutils unit, so they don't work in 3.0.0. Easy. Upgrade your Linux version to 3.0.2.
Actually, I already complained that such a major feature should be in the release documentation, but it isn't.
Technically you can also copy out the helpers from 3.0.2 and compile them with 3.0.0 since the 3.0.0 compiler itself already handled it, but that is more cumbersome than simply upgrading to 3.0.2.