Some Hardware Bug for vstu running imatmul

[Rarity0123]

Issue

I found an issue with vstu.sv running imatmul when the first AXI B response is significantly delayed, while vinsn_queue_d.issue_pnt returns to 0. The failure waveform is shown below.

As observed, when axi_b_valid is asserted, the condition in the combinational circuit of vstu.sv does not match, causing the entire system to stall.

[mp-17]

Thanks a lot, I will fix this asap!