New feature: DSE - Remove variables that do not affect the returned value?

[jcrodriguez1989]

Eliminate all those variables that are assigned, read or not, but that do not affect the value returned by the function.

For example:

foo <- function() {
  a <- 8818
  b <- 0
  c <- 1000
  res <- 0
  for (b < c) {
    b <- b + 1
    res <- res + b
  }
  return(a ^ 2)
}

Would be equivalent to:

foo <- function() {
  a <- 8818
  return(a ^ 2)
}