Inherit JSFunction from JSClosure

[kateinoigakukun]

There is no reason not to make JSClosure to be compatible with JSFunction. We can treat JSClosure as a JSFunction and call it from not only JavaScript but also Swift.

[github-actions[bot]]

Time Change: +495ms (5%) 🔍

Total Time: 9,795ms

Test name	Duration	Change
Serialization/JavaScript function call through Wasm import	21ms	+2ms (11%)	⚠️
Serialization/JavaScript function call through Wasm import with int	15ms	+1ms	🔍
Serialization/JavaScript function call from Swift	102ms	+5ms (5%)	🔍
Serialization/Swift Int to JavaScript with assignment	342ms	+23ms (6%)	🔍
Serialization/Swift Int to JavaScript with call	1,008ms	+52ms (5%)	🔍
Serialization/JavaScript Number to Swift Int	312ms	+16ms (5%)	🔍
Serialization/JavaScript String to Swift String	3,838ms	+217ms (5%)	🔍

View Unchanged

| Test name | Duration | Change | | :--- | :---: | :---: | | Serialization/Swift String to JavaScript with assignment | 391ms | +15ms (3%) | | Serialization/Swift String to JavaScript with call | 1,059ms | +44ms (4%) | | Object heap/Increment and decrement RC | 2,694ms | +118ms (4%) |

View Baselines

| Test name | Duration | | :--- | :---: | | Serialization/Call JavaScript function directly | 3ms | | Serialization/Assign JavaScript number directly | 3ms | | Serialization/Call with JavaScript number directly | 4ms | | Serialization/Write JavaScript string directly | 3ms | | Serialization/Call with JavaScript string directly | 3ms |