Prioritized using caller saved registers over callee saved registers, fixed bug when passing constant int<128> to functions, improved saving of XR and elimited all warnings in the aarch64 backend.

Also modified some of the rust tests so that they are applicable to aarch64.

Added support for generation of unscaled immediate memory offsets.
Fixed compilation errors.
Modified calling of the c 'exit' function in tests so that it will expect a int<64> instead of an int<32>.
Modified formating of various IR things (like Value's and Instructions) to be more easillly readable.

macro.

immiediate number. Richards benchmark runs.