jdk.internal.reflect.ReflectionFactory and SecurityManager

[Martin Buchholz]

Relatedly, I'm writing whitebox jtreg tests and would like to use
VarHandles to access internal data structures.
Because I have:

 * @modules java.base/java.util.concurrent:open

I can use reflection with setAccessible to obtain a usable Field, but if I
try to turn that into a VarHandle I get:

        Field f = ConcurrentLinkedQueue.class.getDeclaredField("head");
        f.setAccessible(true);
        VarHandle v = java.lang.invoke.MethodHandles.lookup()
            .unreflectVarHandle(f);

 java.lang.IllegalAccessException: member is private to package:
java.util.concurrent.ConcurrentLinkedQueue.head/java.util.concurrent.ConcurrentLinkedQueue$Node/getField,
from WhiteBox (unnamed module @7a187f14)

It seems wrong to have this sort of mismatch - setAccessible works, but the
strictly more powerful VarHandles remain unobtainable.

I happen to have a workaround, but I don't see a general solution for
whitebox testing.