swift234

[overflow] Remove signed and unsigned overflow checks if we executed a stronger trap before the current one.

func foo(x : Int) {
  sink(x - 9)  // keep (this is the first overflow check)
  sink(x - 2)  // remove
  sink(x - 3)  // remove
  sink(x - 5)  // remove
  sink(x - 10) // keep (not guarded by the first overflow check)
  sink(x - 5)  // remove
}

Swift SVN r26013