initial import of Mesa 19.1.7 into MesaLib.old.

add missed files due to being in subdir called 'core'.
this time into the right place.

merge mesa 19.1.7 into MesaLib.old.

initial import of Mesa 19.1.7 into MesaLib.old.

import the existing Mesa 10.x sources as MesaLib.old while we
handle the upgrade to Mesa 18.x.