Given how many member functions make use of the system instance,
it's likely just better to pass the system instance in on construction.
Makes the interface a little less noisy to use.
SPDX standardizes how source code conveys its copyright and licensing
information. See https://spdx.github.io/spdx-spec/1-rationale/ . SPDX
tags are adopted in many large projects, including things like the Linux
kernel.
It used to be the case that frame advance skipped duplicate frames
(i.e. it would take 30 frame advances to get through one second
of emulated time in a 30 fps game), but this broke in 9c5c3c0.
Skipping duplicate frames making TASing less annoying.
Makes the global variable follow our convention of prefixing g_ on
global variables to make it obvious in surrounding code that it's not a
local variable.
Normalizes all variables related to statistics so that they follow our
coding style.
These are relatively low traffic areas, so this modification isn't too
noisy.
