opt: dynamic set stack size of emu

[Maxpicca-Li]

Solve PR 355 more elegantly.

[poemonsense]

Thanks for the work. This PR looks good. However, I double check the progress of Verilator and find that it would be better to use the predicted stack size provided by Verilator. I'm proposing my ideas to Verilator in https://github.com/verilator/verilator/issues/4799.

If they accept to add the predictedStackSize method, we don't need this argument anymore. Otherwise, we can have this argument added.

[Maxpicca-Li]

OK, that will be a better way to solve this.

[poemonsense]

Our patch for Verilator has been accepted. Next release version of Verilator (v5.026) will come with a dynamic stack resizer using setrlimit. We've updated difftest to avoid explicit setrlimit in our own main() function in https://github.com/OpenXiangShan/difftest/pull/367. This PR is closed. Thanks all for this work.