Function or class to stringify.
Simple string representation.
const fnString = toFunctionString;
fnString(async () => {}) // "[AsyncArrowFunction (anonymous)]"
fnString(function* () {}) // "[GeneratorFunction (anonymous)]"
fnString(function name() {}) // "[Function: name]"
fnString(async function() {}) // "[AsyncFunction (anonymous)]"
fnString(Proxy) // "[NativeFunction: Proxy]"
fnString(class SomeClass {}) // "[class SomeClass]"
Creates a simple string describing a function, similar to
console.log.