[11u] RFR (S) 8221477: Inject os/cpu-specific constants into Unsafe from JVM

[Dmitry Chuyko]

Hello,

Original RFE: https://bugs.openjdk.java.net/browse/JDK-8221477

Original patch mostly applies cleanly except 3 native method deletions 
in Unsafe.java - they are repeated manually.

11u webrev: http://cr.openjdk.java.net/~dchuyko/8221477/webrev.11u.00/

Testing: tier1, tier2.

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Thanks,
-Dmitry