Warning fix.
Use a better default font path on Linux/Mac OS X.

This way people don't have to copy to ~/.ppsspp/flash0.
The override in ~/.ppsspp/PSP/flash0 still works.
Simplify __cpuidex().

Wasn't building 32-bit for me on Ubuntu.
Merge pull request #4276 from unknownbrackets/linux-minor

Improve Linux flash0 path handling, fix __cpuidex() in some gccs