Clarify what happens when main has type bool and has no return statement.
% should be implemented using the srem instruction in LLVM, as mentioned in the DecafLLVM lecture. The old spec described behaviour that was not consistent with the use of srem.
main can return bool. There were two testcases that had bool returns and expected actual output instead of a semantic error. The default return value for bools is ret i1 1.
To simplify the contest, main must still return int for all contest submissions.
Array bounds checking produces undefined behaviour. Compile-time errors, runtime errors, and segfaults are all acceptable outcomes.