code: private void toBoolean(boolean box) {
          Label nonZero = createLabel();
          Label done = createLabel();
          ifZeroComparisonBranch(nonZero, "!=");
          if (box) {
              TypeDesc newType = TypeDesc.forClass(Boolean.class);
              loadStaticField(newType.getRootName(), "FALSE", newType);
              branch(done);
              nonZero.setLocation();
              loadStaticField(newType.getRootName(), "TRUE", newType);
          }
          else {
              loadConstant(false);
              branch(done);
              nonZero.setLocation();
              loadConstant(true);
          }
          done.setLocation();
      }
docs: Converts an int on the stack to a boolean.