add bare-bones set of Java classes for testing

input/Test.java

@@ -0,0 +1,7 @@
+public class Test {
+
+  public static void main(String[] args) {
+    int a = 2 + 2;
+  }
+
+}

input/java/lang/Class.java

@@ -0,0 +1,7 @@
+package java.lang;
+
+public final class Class <T> {
+  private Object body;
+
+  private Class() { }
+}

input/java/lang/Object.java

@@ -0,0 +1,47 @@
+package java.lang;
+
+import vm.VM;
+
+public class Object {
+  protected Object clone() {
+    return VM.clone(this);
+  }
+
+  public boolean equals(Object o) {
+    return this == o;
+  }
+
+  protected void finalize() { }
+
+  public final Class<? extends Object> getClass() {
+    return VM.getClass(this);
+  }
+
+  public int hashCode() {
+    return VM.hashCode(this);
+  }
+
+  public final void notify() {
+    VM.notify(this);
+  }
+
+  public final void notifyAll() {
+    VM.notifyAll(this);
+  }
+
+  public String toString() {
+    return VM.toString(this);
+  }
+
+  public final void wait() {
+    VM.wait(this);
+  }
+
+  public final void wait(long timeout) {
+    VM.wait(this, timeout);
+  }
+
+  public final void wait(long timeout, int nanos) {
+    VM.wait(this, timeout, nanos);
+  }
+}

input/java/lang/String.java

@@ -0,0 +1,8 @@
+package java.lang;
+
+public final class String {
+  private byte[] bytes;
+  private int offset;
+  private int length;
+  private int hash;
+}

input/java/lang/Throwable.java

@@ -0,0 +1,6 @@
+package java.lang;
+
+public class Throwable {
+  private String message;
+  private Object trace;
+}

input/vm/VM.java

@@ -0,0 +1,21 @@
+package vm;
+
+public class VM {
+  public static native Object clone(Object o);
+
+  public static native Class<? extends Object> getClass(Object o);
+
+  public static native int hashCode(Object o);
+
+  public static native void notify(Object o);
+
+  public static native void notifyAll(Object o);
+
+  public static native String toString(Object o);
+
+  public static native void wait(Object o);
+
+  public static native void wait(Object o, long timeout);
+
+  public static native void wait(Object o, long timeout, int nanos);
+}