Reproduction steps:
1. Open attached project "AssignmentBug"
2. Build scene "Demo" with IL2CPP
--- In the console you will see "TEST: 44, 300, 400, 300"
--- It should actually print (and does print with Mono) "TEST: 300, 300, 400, 300"

This code generates incorrect value:
byte b = 100;
int i = 200;
bool CarryFlag = false;
var newValue = b + i + (CarryFlag ? 1 : 0);

After executing this code newValue will be set to 44.