The sun.font implemenation package in the java.desktop module has
native code that defines a cached glyph image as a C struct.
These are created by native code, and rendered by native code.
But the references to them are cached in Java code, and sometimes
the Java code needs to access fields of these structs.
Currently it does this using jdk.internal.misc.Unsafe for native memory access.
This can be migrated to use FFM APIs.