add a chip playground

in debug menu

src/engine/platform/ay8930.h

@@ -58,6 +58,8 @@ class DivPlatformAY8930: public DivDispatch {
     bool isStereo();
     bool keyOffAffectsArp(int ch);
     void notifyInsDeletion(void* ins);
+    void poke(unsigned int addr, unsigned short val);
+    void poke(std::vector<DivRegWrite>& wlist);
     int init(DivEngine* parent, int channels, int sugRate, unsigned int flags);
     void quit();
 };