still ensure we assert for negative manufacturer data

Author: gfwilliams

src/jsvar.c

@@ -4741,6 +4741,7 @@ JsVar *jsvNewArrayBufferWithPtr(unsigned int length, char **ptr) {
 
 JsVar *jsvNewArrayBufferWithData(JsVarInt length, unsigned char *data) {
   assert(data);
+  assert(length>=0);
   if (length<0) return 0;
   JsVar *dst = 0;
   JsVar *arr = jsvNewArrayBufferWithPtr((unsigned int)length, (char**)&dst);