RFR [9] 8137056: Move SharedSecrets and interface friends out of sun.misc

[Chris Hegarty]

In preparation for JEP 260 "Encapsulate Most Internal APIs” [1],
SharedSecrets and friend interfaces should be moved out of
'sun.misc’ [2] and located in a truly private package. This is so that
they are not part of the proposed to be exported ‘sun.misc'
package.

http://cr.openjdk.java.net/~chegar/8137056.00/

-Chris.

[1] https://bugs.openjdk.java.net/browse/JDK-8132928
[2] https://bugs.openjdk.java.net/browse/JDK-8137056