broadcom/compiler: detect unifa write from signal

It is possible for some signals to write to unifa directly. We will
enable this from ldunif shortly so we should check for it here.

Reviewed-by: Alejandro Piñeiro <apinheiro@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18667>

src/broadcom/qpu/qpu_instr.c

@@ -773,6 +773,12 @@ v3d_qpu_writes_unifa(const struct v3d_device_info *devinfo,
                     inst->alu.mul.waddr == V3D_QPU_WADDR_UNIFA) {
                         return true;
                 }
+
+                if (v3d_qpu_sig_writes_address(devinfo, &inst->sig) &&
+                    inst->sig_magic &&
+                    inst->sig_addr == V3D_QPU_WADDR_UNIFA) {
+                        return true;
+                }
         }
 
         return false;