Fix vram mirror issue on 32-bit.

Fixes #6249.
softgpu: Align spline patches, keep buffer.

Fixes misalignment warning on 32-bit.
Add debug interface for non-L0 texture preview.
Add buttons to select texture level in ge debugger.
Fix some type conversion warnings.
Merge pull request #6335 from unknownbrackets/debugger

Add texture level preview to GE debugger