Unable to complete all tasks

[Lizhooh]

Can not finish 7 tasks on my computer, sometimes only finished 5, sometimes there will be errors.

nodejs v8.5 win7 x64 i5-4300U

[fs-eire]

This is a combination of 2 issues.

for 1), Assertion failed: `workerId < _workers.size()`. This is being fixed in #109 and will be included in next patch release.
for 2), Random crash on node 8.5.0 or higher when executing memory consuming js code in napa zone. Same issue to #96. This is also tracked in nodejs/node#16658. We are following this issue.

[helloshuangzi]

fixed with #109