一部の JSON::operator =(...) が古い内容を消去していなかったバグを修正

[Reputeless]

# include <Siv3D.hpp> // Siv3D v0.6.13

void Main()
{
	{
		JSON json;
		json[U"cc"] = 123;
		Print << json;

		Print << U"================";

		JSON a, b;
		a[U"a"] = 1;
		b[U"b"] = 3;
		json = { {U"aa", a}, {U"bb", b} };

		Print << json;
	}

	while (System::Update())
	{

	}
}

# include <Siv3D.hpp> // Siv3D v0.6.13

void Main()
{
	{
		JSON json;
		json.push_back(100);
		json.push_back(200);
		Print << json;

		Print << U"================";

		json = Array{ 300, 400, 500 };
		Print << json;
	}

	while (System::Update())
	{

	}
}