SonarCloud reports coding oddities in ParallelGCThreadsConstraintFunc:
https://github.com/openjdk/jdk/blob/6569b252b9e61e3eed77039c483529154feffbba/src/hotspot/share/gc/shared/jvmFlagConstraintsGC.cpp#L48-L68

That method followed this structure to separate the constraint functions from Parallel and CMS. Since CMS is removed, we can simplify this by inlining/moving ParallelGCThreadsConstraintFuncParallel to the shared code.