LLVM: make program tests return i8 #2
Description
All program tests under llvm/test/CodeGen/Patmos/programs currently return i32.
This is not optimal, since (on at least Linux) that returned values is truncated by the terminal into only 8 bits.
Because of this, all tests are designed to return values between 0 and 255 to ensure sensible return codes to be checked.
We should change the setup such that all tests return i8.