Gamefixes: "Switch to GSdx software rendering when an FMV plays" is hard crashing the emulator

[RedPanda4552]

PCSX2 version:
1.7.0-dev-430,
1.7.0-dev-425

PCSX2 options:
Gamefix: Switch to GSdx software rendering when an FMV plays

Plugins used:
All defaults (GSdx AVX2)

Description of the issue:
Complete emulator crash when the emulator attempts to swap to software rendering.

EmuLog.txt is clean, no signs of problems. The last message is from the emulator attempting to reset GSdx:

Suspending single plugin: GS
Saving GS
Closing GS

How to reproduce the issue:
Enable the "Switch to GSdx software rendering when an FMV plays" gamefix.

Run any game that has a FMV that will trigger the hack (e.g. Gran Turismo 4's opening video).

Last known version to work:
Last tested version from my end is 1.7.0-dev-333. Will update later with more bisects when I have time, unless someone beats me to it.

PC specifications:
Intel Core i7-8700K (factory clocks), GTX 1070 Ti

[tadanokojin]

I will take a look but that gamefix was already a nightmare to begin with. It may end with me killing it rather than trying to fix it.

[PawTM]

After a bit of bisecting, I found that dev build 379 ""works"", but 385 doesn't.
379 also keeps suspending and recovering GSDX during FMVs with the gamefix enabled aswell (Not very related, just the gamefix being broken before already.)