line comment doesn't show for single instruction

[amanuel2]

Fix #12

For file:

inc %edi #comment2

Previous parse:

(program [0, 0] - [1, 0]
  (instruction [0, 0] - [0, 18]
    kind: (word [0, 0] - [0, 3])
    (ident [0, 4] - [0, 8]
      (reg [0, 4] - [0, 8]))
    (int [0, 9] - [0, 10])
    (ident [0, 10] - [0, 18]
      (reg [0, 10] - [0, 18]
        (word [0, 10] - [0, 18])))))

After this PR:

(program [0, 0] - [1, 0]
  (instruction [0, 0] - [0, 8]
    kind: (word [0, 0] - [0, 3])
    (ident [0, 4] - [0, 8]
      (reg [0, 4] - [0, 8])))
  (line_comment [0, 9] - [0, 18]))

[RubixDev]

this looks like it breaks TC assembly, as you just removed the reference to _tc_expr