JOL is broken on module path

[Zheka Kozlov]

Hi!

javac cannot compile a Java project with module-info.java that requires JOL:

module <module> {
    requires jol.core;
}

Error: the unnamed module reads package java.lang from both java.base and
jol.core

The problem is the class JOLUnsafeTrampoline which is in the java.lang
package. This causes a split package error.

I propose the following simple solution. Since the class is injected via
Unsafe::defineAnonymousClass, we can put it anywhere in the JAR. For
example, we can put it in the root without the .class extension (so Java
will not treat it as a class file).

What do you think?