o3cpu: commit: changes interrupt handling

o3cpu: commit: changes interrupt handling
Currently the commit stage keeps a local copy of the interrupt object.
Since the interrupt is usually handled several cycles after the commit
stage becomes aware of it, it is possible that the local copy of the
interrupt object may not be the interrupt that is actually handled.
It is possible that another interrupt occurred in the
interval between interrupt detection and interrupt handling.

This patch creates a copy of the interrupt just before the interrupt
is handled. The local copy is ignored.