RFR(S) 8223050: JVMCI: findUniqueConcreteMethod() should not use Dependencies::find_unique_concrete_method() for non-virtual methods

[dean.long at oracle.com]

https://bugs.openjdk.java.net/browse/JDK-8223050
http://cr.openjdk.java.net/~dlong/8223050/webrev/

Avoid generating unnecessary dependencies for methods that can be 
statically bound.  While working on this I discovered that Graal's 
HotSpotResolvedJavaMethodImpl.canBeStaticallyBound() doesn't match that 
of the VM, because it was missing a check for <init>.

dl