contract C {
    fn f(bool _b) -> (u256) {
        if (_b) return 1;
        else return 0;
    }

    fn g(bool _in) -> (bool _out) {
        _out = _in;
    }
}
// ====
// compileToEwasm: also
// compileViaYul: also
// ----
// f(bool): 0x0  -> 0x0
// f(bool): 0x1  -> 0x1
// f(bool): 0x2  -> FAILURE
// f(bool): 0x3  -> FAILURE
// f(bool): 0xff  -> FAILURE
// g(bool): 0x0  -> 0x0
// g(bool): 0x1  -> 0x1
// g(bool): 0x2  -> FAILURE
// g(bool): 0x3  -> FAILURE
// g(bool): 0xff  -> FAILURE