Wrong tree produced for binary minus without surrounding spaces

[Timothy Clem]

@ivar-1

For that ruby code, tree-sitter currently produces this incorrect tree:

(program [0, 0] - [1, 0]
  (method_call [0, 0] - [0, 7]
    (instance_variable [0, 0] - [0, 5])
    (argument_list [0, 5] - [0, 7]
      (unary [0, 5] - [0, 7]
        (integer [0, 6] - [0, 7])))))

If you add in the spaces like so, you get the right tree.

@ivar - 1

(program [0, 0] - [1, 0]
  (binary [0, 0] - [0, 9]
    (instance_variable [0, 0] - [0, 5])
    (integer [0, 8] - [0, 9])))