add test for sun.misc.Unsafe functionality

classpath/avian/Machine.java

@@ -10,8 +10,16 @@
 
 package avian;
 
+import sun.misc.Unsafe;
+
 public abstract class Machine {
 
+  private static final Unsafe unsafe = Unsafe.getUnsafe();
+
   public static native void dumpHeap(String outputFile);
 
+  public static Unsafe getUnsafe() {
+    return unsafe;
+  }
+
 }

classpath/sun/misc/Unsafe.java

@@ -0,0 +1,49 @@
+package sun.misc;
+
+public final class Unsafe {
+  private void Unsafe() { }
+
+  private static final Unsafe Instance = new Unsafe();
+
+  public static Unsafe getUnsafe() {
+    return Instance;
+  }
+
+  public native long allocateMemory(long bytes);
+
+  public native void setMemory(long address, long count, byte value);
+
+  public native void freeMemory(long address);
+
+  public native byte getByte(long address);
+
+  public native void putByte(long address, byte x);
+
+  public native short getShort(long address);
+
+  public native void putShort(long address, short x);
+
+  public native char getChar(long address);
+
+  public native void putChar(long address, char x);
+
+  public native int getInt(long address);
+
+  public native void putInt(long address, int x);
+
+  public native long getLong(long address);
+
+  public native void putLong(long address, long x);
+
+  public native float getFloat(long address);
+
+  public native void putFloat(long address, float x);
+
+  public native double getDouble(long address);
+
+  public native void putDouble(long address, double x);
+
+  public native long getAddress(long address);
+
+  public native void putAddress(long address, long x);
+}