sun.misc.GC is not "Critical APIs", as defined by JEP 260, so should be moved out of sun.misc
 and placed into a more appropriate package, where it can be encapsulated.

Since GC is only used by RMI, I proposed to move it to the java.rmi module. Since it has
a native component, and no other code in java.rmi has, then a new small native library
is required.