message: replace size_t with uint64_t
diff: @@ -3012,7 +3012,7 @@ TEST(BuilderTest, UsePaddingForTwoByteArray) {
  b.clear();
  b.openArray();
  - for (size_t i = 0; i < 260; ++i) {
  + for (std::uint64_t i = 0; i < 260; ++i) {
  b.add(Value(i));
  }
  @@ -3222,7 +3222,7 @@ TEST(BuilderTest, UsePaddingForTwoByteObject) {
  b.clear();
  b.openObject();
  - for (size_t i = 0; i < 260; ++i) {
  + for (std::uint64_t i = 0; i < 260; ++i) {
  b.add(Value(std::string("test") + std::to_string(i)));
  b.add(Value(i));
  }
  