FunC incorrectly optimizes away division by zero for operator / together with >=

[jeshecdom]

Based on tact-lang/tact#3019

Code to reproduce

int calc(int x) {
    return ((0 / x) >= 0);
}

() main() {
    throw_if(16, calc(0));
}

Output Fift

// automatically generated from `func_test.fc` 
DECLPROC calc
DECLPROC main
calc PROC:<{
  DROP
  TRUE
}>
main PROC:<{
  0 PUSHINT
  calc CALLDICT
  16 THROWIF
}>

Actual behavior when executed

calc always returns true.

Expected behavior when executed

Exit code 4, since 0 / x should produce a division by zero when x = 0.

Side note 1: We can produce a related expression that also gets mapped into TRUE by replacing 0 with other expression that is equal to 0. For example, the following expressions also get transformed into TRUE in Fift, but they should produce error code 4 on the provided value for x:

• (~(-1) / x) >= 0 for x = 0.
• ((1 & (~ 1)) / x) >= 0 for x = 0.
• ((x & 0) / x) >= 0 for x = 0.
• ((x * 0) / x) >= 0 for x = 0.

Side note 2: The related expression (0 / x) == 0 DOES get translated to Fift in the expected way:

calc PROC:<{
  0 PUSHINT
  SWAP
  DIV
  0 EQINT
}>