For some reason, the stack refuses to grow with the latest MSVC updates,
at least within our unit tests that bump the stack considerably within
a lambda function.
Just force the commit size to 1MB for now.
Instead of shoehorning GS source files into the unit tests, we link with
the full PCSX2 core library. We stub out all the Host functions, as,
well, there isn't one, and they may be indirectly referenced.
Fix codegen on x86-64
Part 1 of the changes being worked on in #3451
Makes x86emitter emit the x86-64 machine code you would expect it to
Also adds some unit tests to verify that things are working