Bug 1839070 - Emit a start point if close is called immediately after move_to....

Bug 1839070 - Emit a start point if close is called immediately after move_to. r=jrmuizel, a=dmeehan


wpf-gpu-raster would blindly modify the last point type in a path when call was closed, even
if move_to preceded it directly and outputted no actual point type. In this case, we need to
ensure that we emit a start point if close is called immediately after move_to.

Differential Revision: https://phabricator.services.mozilla.com/D181358