RFR [9] 8153756: jdk.vm.ci should not depend on sun.misc ( jdk.unsupported module )

[Chris Hegarty]

Refactoring due to JEP 260 [1] has moved the "real" Unsafe to
jdk.internal.misc. All JDK modules, if they require Unsafe,
should depend on a qualified export of jdk.internal.misc from
the base module, rather than Unsafe in the jdk.unsupported module.
The base module already exports jdk.internal.misc to the jdk.vm.ci
module.

This issue updates all usages of sun.misc.Unsafe to
jdk.internal.misc.Unsafe, in the jdk.vm.ci module.

http://cr.openjdk.java.net/~chegar/8153756/
https://bugs.openjdk.java.net/browse/JDK-8153756

The webrev is against jdk9/dev, but I intend to push this through
hs-comp.

-Chris.

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