SkyEye dyncom interpreter

Integrates the SkyEye "dyncom" interpreter (from sourceforge.net/p/skyeye/code/ci/master/tree/arch/arm/dyncom/). This is a faster, more modern ARM11 interpreter core, used by the SkyEye project as a "hybrid" mode with their dynamic recompiler. I'd like to get some feedback/testing done with this PR before being merged. By default, the new interpreter is not enabled, but can be with the following patch:

https://gist.github.com/bunnei/c1b14a760fb9190e97bd

Furthermore, if interested in seeing the best performance with yeti3DS (and other homebrew), try the following speedhack (I've yet to find a correct workaround, hence why I won't be committing this):

https://gist.github.com/bunnei/702a6b6449d8f7b6216d


Minimally modified, aside from somewhat regular bug fixes. I'm not sure that I'm convinced one way or another: On one hand, it is external code, and does not conform with our code base stylistically. On the other hand, it's a crutch of the project, we're not really an emulator without a CPU core, and we probably won't rewrite this anyway (if/when we do write a CPU core, I'm sure it'll be a recompiler).

At any rate, it's a valid point, but again, not something I'd like to address with this PR.