systemc: Track event sensitivities with a list instead of a set.
systemc: Track event sensitivities with a list instead of a set.

It's totally legal to signal that an event happened to waiting
processes in any order we choose, but to match the order of events
which appears in the Accellera test golden output, we need to do things
in the order they did. This is less efficient, but will reduce the
number of false positives.

Change-Id: Ie2882249ae846991d627f5f688a9e89e629bb300
Reviewed-on: https://gem5-review.googlesource.com/c/12612
Reviewed-by: Gabe Black <5c8aa1266c03186393d9e7b3b4e3b14239af8201@google.com>
Maintainer: Gabe Black <5c8aa1266c03186393d9e7b3b4e3b14239af8201@google.com>

gem5/gem5,gem5/gem5,gem5/gem5,TUD-OS/gem5-dtu,TUD-OS/gem5-dtu,gem5/gem5,TUD-OS/gem5-dtu,gem5/gem5,TUD-OS/gem5-dtu,gem5/gem5,TUD-OS/gem5-dtu,gem5/gem5,TUD-OS/gem5-dtu,TUD-OS/gem5-dtu