Correctly initialize the SrcItem.iCursor field to -1 when creating a co-routine from a multi-values VALUES clause.

FossilOrigin-Name: c32953ff6d72910815eaff29ab1b790c412e1a741d02c03c5911dda0c08e5130

src/insert.c

@@ -635,6 +635,7 @@ Select *sqlite3MultiValues(Parse *pParse, Select *pLeft, ExprList *pRow){
       p->fg.viaCoroutine = 1;
       p->addrFillSub = sqlite3VdbeCurrentAddr(v) + 1;
       p->regReturn = ++pParse->nMem;
+      p->iCursor = -1;
   
       sqlite3VdbeAddOp3(v,OP_InitCoroutine,p->regReturn,0,p->addrFillSub);
       sqlite3SelectDestInit(&dest, SRT_Coroutine, p->regReturn);