For some reason the decomp version is doing the first xor in
EnableFullScreen with the operands swapped. The source code and
the original binary both have m_flags ^ e but the decomp binary has e ^
m_flags. This gives the same result but it is not a 100% match in the
binary. I'm not sure why the compiler is doing this or how to
change it but the other inaccuracy with the function is fixed.