Takes the logic from Jit64 and moves it into DivUtils, so it can be reused by other backends as well.
SPDX standardizes how source code conveys its copyright and licensing information. See https://spdx.github.io/spdx-spec/1-rationale/ . SPDX tags are adopted in many large projects, including things like the Linux kernel.
Two unit tests were in the root UnitTests folder and were not being built when using CMake.
