Remove workaround for truncated last lines (dart-lang/stack_trace#100)

The referenced SDK issue has been closed.
https://github.com/dart-lang/sdk/issues/23614

Remove the workaround that handles the last line specially and simplify
to a collection for loop.
1 file changed
tree: 5141441d0584d493d2207a9bedfacf438e3bdd49
  1. pkgs/