PLC010: <ngMacroName>
and the NGMUX <ngmuxDriverType driver>, <driverMacroName>,
are put in the same middle CCC location.
NGMUX contains three macros: an NGMUX macro and two
global net drivers. The global net assigner places these three macros
together in the same middle CCC location (that is, either the middle-left
or middle-right CCC location).