Horizontal scrollbar in calc is broken in RTL interface. No
scroll handle is available, and the left and write arrows function incorrectly.

Current behavior:
1. The horizontal scrollbar shows no "handle" to drag.
2. Clicking on the arrows to the side of the horizontal scrollbar works, but
inversely. The right arrow scrolls to the left, the left arrow scrolls to the
right.

Expected behavior:
1. The horizontal scrollbar at the bottom of calc window should show a
handle.
2. Clicking on the right arrow should scroll to the right, clicking on the left
arrow should scroll to the left.