GS: Support upscaled region repeat

[TellowKrinkle]

Description of Changes

• Add support for upscaling region repeat
• Adjust region clamp coordinates for upscaling

Rationale behind Changes

More upscaling is nice

Suggested Testing Steps

• Make sure my changes to region clamp didn't make things worse. I don't think they would, but who knows
• Test DX and GL (I only tested Metal and Vk)
• Test upscaled region repeat. If you don't know of a game to test, comment out GSRendererHW:1373-1378 and GSRendererHW:1387-1391 and run this trace

[refractionpcsx2]

Apparently this makes #5851 worse? I assume it was meant to address that.

[TellowKrinkle]

If it's the last commit causing it, I mostly wanted to see what that did affect, and had no specific games in mind when I changed it

It makes it more in line with what our hw sampler would do to a similar upscale, which is nice as I don't have to worry about side effects of swapping between the two.

The change is to how clamping is handled. The PS2 clamps with min and max values, rather than min and max+1. This means that if you upscale a 4x4 texture to 16x16, the equivalent max value goes from 3 to 12, rather than 3 to 15. Obviously if you use a hw sampler, clamping goes to the edge of the texture, which will of course be 15. #5851 being affected by both this and #5387 makes sense though, since #5387 is what enabled clamping with the hw sampler when available, which this adjustment is attempting to match in the sw sampler.

[seta-san]

can we please rebase this? there are a couple games I'd like to test it with.

[Uzarkis]

@TellowKrinkle - Will you make new updates to this? Or will you close this request? Do you need any more tests from us?

[TellowKrinkle]

It reveals a whole bunch more upscaling issues in games, so it's waiting on some improved upscale hacks which I keep not getting around to working on