mem: Adding PortTerminator

This change adds the source code for the PortTerminator SimObject.
It could be used to connect request/response ports in the system
that can not be connected to any other ports. This will prevent
errors caused by orphan ports in the system. As an example if
you have set up a cache hierarchy and do not want to test its
performance in full system mode and want to use PyTrafficGen
instead, your system will end up with an icache or walker ports
that are not connected to anything. In this case, you can use a
PortTerminator to connect the orphan ports in your system.

Change-Id: I5e19cdd3ce064638ffabf29d29225eda77ffc146
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/51609
Tested-by: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jason Lowe-Power <power.jg@gmail.com>
Maintainer: Jason Lowe-Power <power.jg@gmail.com>
4 files changed