Bug fix for flag gpgpu_perf_sim_memcpy

[sun-lingyu]

Hi.

Thank you for your great work of accel-sim!

We find a bug which makes the -gpgpu_perf_sim_memcpy flag not working.

In accel-sim-framework/gpu-simulator/gpgpu-sim/src/gpgpu-sim/gpu-sim.cc, the type of variable wr_addr should be size_t instead of unsigned. Otherwise, it leads to an unexpected type conversion and stores a wrong address in wr_addr.

Since this is a tiny fix, I prefer not to border open a new pull request. Maybe you can fix it soon.

Again thank you very much! :)

[JRPan]

Thank you. You can submit a PR if you want. And you can become a collaborator :)

It would be the same process for us as well. So don't worry about it.

Thanks for pointing it out anyway!