Freezes the observable behavior of TCuboidPart, JCuboidPart and the
TCuboidPart$class bridge before the Java port, per the test-first gate in
JAVA_MIGRATION.md. All cases pass against the untouched Scala.
Records two asymmetries worth preserving: getSubParts wraps the bounds in
an IndexedCuboid6, whose copy constructor makes it a copy carrying a boxed
Integer 0 as data, while getCollisionBoxes aliases the bounds instance
itself. Cuboid6 has no equals, so geometry is compared component-wise.
Also adds a frozen Scala consumer compiled with 2.11.5 against the
reference dev jar at 246daff. Its forwarders call all four $class statics,
so it detects the linkage break that a freshly recompiled test would miss.
ForgeRelocationFMP, OpenComputers, ProjRed and ProjectBlue all depend on
those descriptors.
One case exists specifically to guard the port: TMultiPart supplies empty
getSubParts and getCollisionBoxes, and on the JVM a superclass method beats
an interface default, so a Java interface cannot reproduce Scala trait
linearization on its own.
