Fix[JNA]: use agent to replace class at runtime

Fixes duplicate module package on recent Forge versions.

JavaApp/src/patchjna_agent.txt

@@ -0,0 +1,2 @@
+Agent-Class: net.kdt.patchjna.PatchJNAAgent
+Premain-Class: net.kdt.patchjna.PatchJNAAgent

JavaApp/src/patchjna_agent/net/kdt/patchjna/PatchJNAAgent.java

@@ -0,0 +1,32 @@
+package net.kdt.patchjna;
+
+import java.io.*;
+import java.lang.instrument.ClassFileTransformer;
+import java.lang.instrument.IllegalClassFormatException;
+import java.lang.instrument.Instrumentation;
+import java.lang.reflect.InvocationTargetException;
+import java.security.ProtectionDomain;
+
+public class PatchJNAAgent implements ClassFileTransformer {
+    public byte[] transform(ClassLoader loader, String className, Class<?> classBeingRedefined,
+    ProtectionDomain protectionDomain, byte[] classfileBuffer) throws IllegalClassFormatException {
+        byte[] transformeredByteCode = classfileBuffer;
+        if (className.equals("com/sun/jna/Platform")) {
+            System.out.println("PatchJNAAgent: Replacing class");
+            try {
+                InputStream inputStream = PatchJNAAgent.class.getClassLoader().getResourceAsStream("com/sun/jna/Platform.class.patch");
+                transformeredByteCode = new byte[inputStream.available()];
+                DataInputStream dataInputStream = new DataInputStream(inputStream);
+                dataInputStream.readFully(transformeredByteCode);
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+        return transformeredByteCode;
+    }
+
+    public static void premain(String args, Instrumentation instrumentation) {
+        System.out.println("PatchJNAAgent: premain called");
+        instrumentation.addTransformer(new PatchJNAAgent());
+    }
+}