Move HotSpot-AOT packages to upstream Graal repo

To simplify development and merges it'd be great to move all packages under jdk/open/src/jdk.aot/share/classes to upstream Graal repo. That should allow us:
1. Add unit tests for aot that would be run in graal gate to ensure there is no breakage to aot as early in the repo hierarchy as possible.
2. Simplify the development process by allowing to use the Graal repo as a base for development. This will also simplify merges in the presence of renaming.

The result of the move should include an mx command to run aot, and include the aot packages in the updategraalinopenjdk mx command which should land them in jdk/open/src/jdk.aot/share/classes.