===========test.js===========
for (let i = 0; i < 50; i++) {
  try {
    const arr = [100, 101];
    arr[Symbol.iterator] = Symbol;
    [] = arr;
    print("hello")
  } catch (e) {}
}
=========end of test.js======
Run args:
./jsc test.js --useConcurrentJIT=0 --jitPolicyScale=0

JSC wrongly print "hello" in baselineJIT instead of throwing an exception.