Many source files that are "owned" by Java 2D are scattered throughout
directories that are historically associated with AWT. It would help reduce
confusion if we moved the 2D-owned files into their own logical
directories/packages.

Someday we would like to separate libawt.so/awt.dll into distinct AWT and
Java 2D halves, so this would be a good first step on the path to achieving
that goal.