Toolbars and some other regions are aligned to the left sides of their
areas and have an (often hidden) right edge that can be dragged to
resize or hide it. If there isn't enough vertical space to show all of
its contents then you also get a scroll bar along that same edge. These
two things conflict badly and is almost impossible to use with a tablet
pen. The mouse cursor changes to indicate dragging over the scrollbar
but doesn't work. Dragging the scoll bar requires doing so to the right
of it. This PR moves the scroll bars to the left side of these left-
aligned areas. They are correctly changed to the right side if you flip
the region.
Pull Request: https://projects.blender.org/blender/blender/pulls/136218
3e29f3eaa2