Fixes incorrect logspam when the buffer needed to be reset on flushes (which we already were doing, but 52feed04db moved it to after the check was made). This is https://bugs.dolphin-emu.org/issues/10312.
I also converted it to an assert, as if this does happen, things are going to render incorrectly, so we want to make it obvious.
Rather than makring some parts of VertexLoaderManager dirty in some places and some in others, do it all in VideoState. Also, since CPState no longer contains pointers/non-CP data after d039b1bc0d, we can just use p.Do on it instead of manually saving each field.
This more accurately represents what's going on, and also ends at 0 instead of 1, making some indexing operations easier. This also changes it so that position_matrix_index_cache actually starts from index 0 instead of index 1.
Now works with games that deliberately avoid invalidating TMEM because
they know textures are too large to fit:
* Sonic Riders
* Metal Arms: Glitch in the System
* Godzilla: Destroy All Monsters Melee
* NHL Slapshot
* Tak and the Power of Juju
* Night at the Museum: Battle of the Smithsonian
* 428: Fūsa Sareta Shibuya de
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.
