saveLastBranch :: InstrM LastBranch
saveLastBranch = do
  InstrState { isLastBranch = lb } <- get
  modify' $ \s -> s { isLastBranch = NoBranch }
  return lb
saveLastBranch :: InstrM LastBranch
saveLastBranch = do
  InstrState { isLastBranch = lb } <- get
  modify' $ \s -> s { isLastBranch = NoBranch }
  return lb
saveLastBranch = do
  InstrState { isLastBranch = lb } <- get
  modify' $ \s -> s { isLastBranch = NoBranch }
  return lb