Implement PH7_MemObjSafeStore().

include/ph7int.h

@@ -1650,6 +1650,7 @@ PH7_PRIVATE sxi32 PH7_MemObjToBool(ph7_value *pObj);
 PH7_PRIVATE sxi32 PH7_MemObjToCallback(ph7_value *pObj);
 PH7_PRIVATE sxi32 PH7_MemObjToResource(ph7_value *pObj);
 PH7_PRIVATE sxi32 PH7_CheckVarCompat(ph7_value *pObj, int nType);
+PH7_PRIVATE sxi32 PH7_MemObjSafeStore(ph7_value *pSrc, ph7_value *pDest);
 PH7_PRIVATE sxi64 PH7_TokenValueToInt64(SyString *pData);
 /* lex.c function prototypes */
 PH7_PRIVATE sxi32 PH7_TokenizeRawText(const char *zInput, sxu32 nLen, SySet *pOut);