Small change to build Graal with Lambda repo

[Caspole, Eric]

Hi everybody,
I have been experimenting to build Graal against the jdk 8 lambda tip repo. It seems the args for sun.reflect.Reflection.getCallerClass() changed between JDK 7 and 8.

This one line change allows the build to succeed and I can use this JDK 8 Graal build in NetBeans to run the Junits.
 http://cr.openjdk.java.net/~ecaspole/reflection_args_for_lambda_jdk/webrev.00/

I am not sure there is a JDK 8 branch for Graal, can this be integrated without breaking JDK 7?
Thanks,
Eric