message: Save one word in Alloca
  Summary: Practically useless, but this would be not misleading.
diff: @@ -101,7 +101,7 @@ impl Alloca {
  let mut start = self.alloc.get();
  let mut stop = start.wrapping_add(size_words);
  - if stop >= self.end.get() {
  + if stop > self.end.get() {
  self.allocate_more(layout);
  start = self.alloc.get();
  stop = start.wrapping_add(size_words);
  