...by avoiding `CreateListFromArrayLike` in cases when we could directly
use elements of underlying object's indexed properties storage.
Makes this program go 2.1x faster:
```js
function target(a, b, c) {
return a + b + c;
}
const args = [1, 2, 3];
let result = 0;
(function() {
for (let i = 0; i < 10_000_000; i++) {
result += target.apply(null, args);
}
})();
```
ES 5(.1) described parsing of the function body string as:
https://www.ecma-international.org/ecma-262/5.1/#sec-15.3.2.1
7. If P is not parsable as a FormalParameterList[opt] then throw a SyntaxError exception.
8. If body is not parsable as FunctionBody then throw a SyntaxError exception.
We implemented it as building the source string of a complete function
and feeding that to the parser, with the same outcome. ES 2015+ does
exactly that, but with newlines at certain positions:
https://tc39.es/ecma262/#sec-createdynamicfunction
16. Let bodyString be the string-concatenation of 0x000A (LINE FEED), ? ToString(bodyArg), and 0x000A (LINE FEED).
17. Let prefix be the prefix associated with kind in Table 49.
18. Let sourceString be the string-concatenation of prefix, " anonymous(", P, 0x000A (LINE FEED), ") {", bodyString, and "}".
This patch updates the generated source string to match these
requirements. This will make certain edge cases work, e.g.
'new Function("-->")', where the user supplied input must be placed on
its own line to be valid syntax.