RFR(S) 8191437: AOT doesn't work easily after thread local handshakes

[dean.long at oracle.com]

https://bugs.openjdk.java.net/browse/JDK-8191437

http://cr.openjdk.java.net/~dlong/8191437/webrev.hs/

http://cr.openjdk.java.net/~dlong/8191437/webrev.graal/


This change adds support for thread local handshakes to Graal for x64 
and SPARC.  Graal generates a different instruction encoding on x64 than 
C1/C2, so I had to account for that difference in 
sharedRuntime_x86_64.cpp.  I'm including the Graal changes because I 
would like to push them together with the HotSpot changes.


dl