+Ap |void |gv_init_sv |NN GV* gv|NULLOK HV* stash|NN SV* namesv|int multi|U32 flags
+Ap |void |gv_init_pv |NN GV* gv|NULLOK HV* stash|NN const char* name \
+ |int multi|U32 flags
+Ap |void |gv_init_pvn |NN GV* gv|NULLOK HV* stash|NN const char* name \
+ |STRLEN len|int multi|U32 flags