[cpp] do not omit generation for KGeneric classes by default (see #2016)
[cpp] do not omit generation for KGeneric classes by default (see #2016)

pleclech/hacking-haxe,pleclech/hacking-haxe,pleclech/hacking-haxe,pleclech/hacking-haxe,pleclech/hacking-haxe,pleclech/hacking-haxe