If a lambda expression does not capture any local variables, convert
it to a global free function and replace the lambda creation with
a reference to that function.
Example: for the following Kotlin code
```kotlin
fun foo(f: () -> Unit) = f()
fun bar() = foo { console.log("hello") }
```
before this patch, we generated:
```js
function foo(f) {
return f();
}
function bar() {
return foo(bar$lambda());
}
function bar$lambda() {
return function () {
console.log('hello');
};
}
```
after this patch, we generate:
```js
function foo(f) {
return f();
}
function bar() {
return foo(bar$lambda);
}
function bar$lambda() {
console.log('hello');
}
```
Sergej Jaskiewicz