[JS IR] Lift lambdas that capture no context

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');
}
```

js/js.translator/testData/box/inline/lambdaInLambda.kt

@@ -1,7 +1,9 @@
 // EXPECTED_REACHABLE_NODES: 1284
 package foo
 
-// CHECK_CALLED_IN_SCOPE: scope=multiplyBy2 function=multiplyBy2$lambda
+// CHECK_FUNCTION_EXISTS: multiplyBy2$lambda
+// CHECK_CALLED_IN_SCOPE: scope=multiplyBy2 function=multiplyBy2$lambda TARGET_BACKENDS=JS
+// HAS_NO_CAPTURED_VARS: function=multiplyBy2 except=multiplyBy2$lambda
 // CHECK_NOT_CALLED_IN_SCOPE: scope=multiplyBy2 function=multiplyBy2$lambda_0
 // CHECK_NOT_CALLED_IN_SCOPE: scope=multiplyBy2 function=run
 
@@ -19,4 +21,4 @@ fun box(): String {
     assertEquals(8, multiplyBy2(4))
 
     return "OK"
-}
+}