4.15 dsktune command fails with an unsupported error message

The dsktune command included with the 389 Directory Server base package, 389-ds-base, fails with an error message notifying that the system does not have support for cx16, a feature commonly available on x86 platforms:

ERROR: This system does not support CMPXCHG16B instruction (cpuflag cx16).
nsslapd-enable-nunc-stans must be set to "off" on this system.
In a future release of Directory Server this platform will NOT be
supported.

ERROR  : The above errors MUST be corrected before proceeding.

The dsktune command helps to check that a system meets requirements and can provide information that helps with the configuration, but is not required to run the 389 Directory Server. (Bug ID 26861135)