[ISS] - Tracing updates to link regs     - Model was not providing instructor event on updating the link register     - Added the wr_link_reg variable so that the comparison can make use of it
[ISS] - Tracing updates to link regs
    - Model was not providing instructor event on updating the link register
    - Added the wr_link_reg variable so that the comparison can make use of it

SimpleCPU/SimpleCPU,SimpleCPU/SimpleCPU,SimpleCPU/SimpleCPU