Viewports: fixed outer-right edge of MenuBar clipping rectangle off by one when window is located on a monitor with negative coordinates. (#6861, #2884)
// We don't clip with current window clipping rectangle as it is already set to the area below. However we clip with window full rect.
// We remove 1 worth of rounding to Max.x to that text in long menus and small windows don't tend to display over the lower-right rounded area, which looks particularly glitchy.