FPU: Removed forced rounding on DIV/SQRT/RSQRT (Do Not merge!)

[refractionpcsx2]

Added gamefix for Mortal Kombat Shaolin Monks

Description:

For a very long time PCSX2 has had the rounding mode of DIV, SQRT and RSQRT on the FPU forced to "Nearest" instead of Chop/Zero (unless you use the Neg DIV hack), presumably because it fixed some game and seemed like a good idea. This PR aims to remove it, but it needs to be tested thoroughly before we even think about merging it. I suspect a few games will require a gamefix (like Shaolin Monks did) but many other games might see a positive benefit from doing this.

Please reply below if any game needs any other rounding setting and if it has any adverse effects on the game.

Improvements:
Stuntman - AI is improved (but still not brilliant)
Freakstyle - Less issue with invisible walls
ONI - Interactable doors now fixed

Regressions:
Mortal Kombat Shaolin Monks - Texture sizes, fixed by setting rounding to positive

[boringhexi]

May we also list games that seem unaffected? This could save other testers some time.

Gitaroo Man: Did not notice any new graphical bugs, nor any improvement of the existing graphical bug (i.e. Stage 4 flashing). (Tested 30-60 seconds of each stage including the multiplayer one.)

[RedDevilus]

Better to test several games and mention where you see improvements or more importantly problems like regressions. Unless you want to mention several of the 4K distinct games (or 10K+ entries of the GameDB). Unaffected games don't really lower or speed-up the merging process in this manner. Or you can just say your collection or say something like 10+ are working like before.