Restructuring things in this way brings two immediate benefits:
* Code is deduplicated between Jit64 and JitArm64.
* Materializing an immediate value in a register no longer results in us
forgetting what the immediate value was.
As a more long-term benefit, this lets us also run constant propagation
as part of PPCAnalyst, which could let us do cool stuff in the future
like statically determining whether a conditional branch will be taken.
But I have nothing concrete planned for that right now.
Fusion is one of the built-in styles that Qt ships with, and that is
generally supported in all platforms and handles custom color palettes
properly.
The color palettes have been borrowed from the Dolphin Memory Engine
buddy application.
The new styles are:
- **Fusion Light**
- **Fusion Dark Gray**
- **Fusion Dark**
A demo of each style on Windows:
| System | Light | Dark | Fusion Light | Fusion Dark Gray | Fusion Dark |
| ------ | ----- | ---- | ------------ | ---------------- | ----------- |
| <img width="1920" height="1080" alt="Dolphin Emulator System style" src="https://github.com/user-attachments/assets/7f55a19d-d9a1-43d1-a435-1e1d5b29abe2" /> | <img width="1920" height="1080" alt="Dolphin Emulator Light style" src="https://github.com/user-attachments/assets/4c70f2f9-16b8-4777-b72b-55b2dffcd1e4" /> | <img width="1920" height="1080" alt="Dolphin Emulator Dark style" src="https://github.com/user-attachments/assets/5e669477-d2a5-4d19-b2c5-a2ed9bb1e6fe" /> | <img width="1920" height="1080" alt="Dolphin Emulator Light Fusion style" src="https://github.com/user-attachments/assets/b1f95c47-0691-4809-bd74-99e913c17684" /> | <img width="1920" height="1080" alt="Dolphin Emulator Dark Gray Fusion style" src="https://github.com/user-attachments/assets/c9d30aa3-f941-4fc5-806f-d3fbd2cae0cc" /> | <img width="1920" height="1080" alt="Dolphin Emulator Dark Fusion style" src="https://github.com/user-attachments/assets/123d2125-e126-4e8c-aa42-793ded8ffacc" /> |
> [!NOTE]
> Notice that the **Light** and **Dark** styles remain available only on
> Windows due to limitations on how styles in the various platforms
> handle (or mishandle) custom color palettes.
> [!IMPORTANT]
> Due to [`KDE-511547`](https://bugs.kde.org/show_bug.cgi?id=511547),
> after having used Breeze (default style in Plasma systems), top tool
> bars in tools areas will lose their correct background color; a
> restart will be required in order to get the updated color in the main
> window.
>
> UPDATE: The issue has been fixed upstream and should be available in
> KDE Plama 6.5.3 and newer.
