[NFC][IRCE] Add unit test to show room for improvement (#71506)

Add tests for compound loop bounds where IRCE is possible

if (K > 0 && M > 0)
  for (i = 0; i < min(K, M); i++) {...}

if (K > 0 && M > 0)
  for (i = min(K, M); i >= 0; i--) {...}

Co-authored-by: Aleksander Popov <apopov@azul.com>