The unreachable_code_linter should also mark code inside if, else, for, and while loops as unreachable, especially when a return or stop function is called.

The following code currently generates only one annotation:

x <- function() { 
  if(TRUE) { 
    stop('This is a test') 
    5+5 
  } 
  return(5L)
  4+4 
} 

And this one generates none:

x <- function() { 
  if(TRUE) { 
    stop('This is a test') 
    5+5 
  } 
  4+4 
}