if (VM.VerifyAssertions) VM.assert(t.isClassType());
if (VM.VerifyAssertions) VM._assert(t.isClassType());
  public static void allocateThinLock(VM_Type t) {    if (t.thinLockOffset == -1) {      if (VM.VerifyAssertions) VM.assert(t.isClassType());      VM_Class klass = t.asClass();      int fieldOffset = objectEndOffset(klass) - 4; // layout field backwards!      klass.thinLockOffset = fieldOffset;      klass.increaseInstanceSize(4);    }  }