The thrsw will invalidate rtop, just like accumulators and flags. Caught
by simulator assertions in CS imulextended/umulextended tests.
Fixes: 90269ba35333 ("broadcom/vc5: Use THRSW to enable multi-threaded shaders.")
for (int i = 0; i < ARRAY_SIZE(state->last_r); i++)
add_write_dep(state, &state->last_r[i], n);
add_write_dep(state, &state->last_sf, n);
+ add_write_dep(state, &state->last_rtop, n);
/* Scoreboard-locking operations have to stay after the last
* thread switch.