[CIR][ThroughMLIR] Lower WhileOp with break.

[terapines-osc-cir]

The PR1735 contains too many conflicts with the main branch.

Got it re-patched to the current main branch.

This only deals with the case in which the break is directly under the loop, not nested in any ifs.
In this case we simply erase the loop as well as unreachable code after that break.

[bcardosolopes]

I was looking at the generated IR and I'm not sure this works right, the loop is gone but you still need to increment i, what am I missing here?

[terapines-osc-cir]

It's the 2nd i++ (operations after break) that got removed, the 1st i++ is kept.

  while (i < 100) {
    i++;
    break;
    i++;
  }