code: private VarSymbol enterConstant(String name, Type type) {
          VarSymbol c = new VarSymbol(
              PUBLIC | STATIC | FINAL,
              names.fromString(name),
              type,
              predefClass);
          c.setData(type.constValue());
          predefClass.members().enter(c);
          return c;
      }
docs: Enter a constant into symbol table.
  @param name   The constant's name.
  @param type   The constant's type.