ppc64le JIT now officially landing (again) in DOSBox Staging

Waaaay back when, I wrote up a basic dynamic recompilation JIT for vanilla DOSBox (the most well-known of the DOS-specific emulators, if you've been under a rock for awhile), which increases performance in x86 protected mode by as much as several times. This was an unofficial patch and I just kept it out of the tree, since the 32-bit PowerPC JIT it was based on wasn't part of it either.

Well, little did I know, but the patch got picked up as part of the DOSBox Staging spin six months later and apparently ran fine until an upstream commit broke it. I never noticed because I was happily using my old build, but Trung Lê did and reported it. So I fixed it and added proper support for 4K or 64K page sizes, and it was committed to the source tree today as part of 0.81. If you can't wait, build from source today, or wait for your package manager to pick it up whenever 0.81 gets formally released.