When a for, while, or do/while loop contains a break or continue statement at the top level of the loop's body, and the break or continue statement is not the last statement in the block, then ClangIR fails validation.

void test(int x) {
  for (int i = 0; i < x; ++i) {
    break;
    --x;
  }
}

loc("for-break.cpp":3:5): error: 'cir.yield' op must be the last operation in the parent block
fatal error: error in backend: CIR codegen: module verification error before running CIR passes

If the break or continue is in a nested scope within the loop (which is the normal case in real code), there is no error. If the break or continue statement is the last statement in the block then there is a different internal error which is covered by #324.