Range miscalculation when using Let expressions

[jfmengels]

module TestModule exposing (..)

a =
  let
    c = 1
  in
  2
  
-- hello

b = 3

In the code above, the range for a is considered to be

{ start = { row = 3, column = 1 }
, end = { row = 11, column = 1 }
}

This is incorrect, as that would mean that a's range ends where b starts. Also, that means that removing the a node means deleting the comment in between a and b (which is how I noticed the problem).

If the let expression is removed, like here:

a =
  2
  
-- hello

b = 3

then a's range is correct and equal to

{ start = { row = 3, column = 1 }
, end = { row = 4, column = 4 }
}

Interactive Ellie with it at: https://ellie-app.com/99hdDGwS24La1