Code generated for optional call could be optimized when the result is unused

The generated code for optional chaining is a little verbose when the "return" value of the expression is not being used. For example, when simply calling a function: ```typescript maybe.close?.() ``` Here is a more [complete example](https://www.typescriptlang.org/play/#code/C4TwDgpgBAsghiARhAwgGwPYGc6LdAXigG8BYAKCigGNMsIB+ALigAoBKKAgPhIF8A3BUEUKAEwi04AJ2jUMAOyzAoAWwTIW8JKjq58Q8gHojAeQXQMYYAEtFcNBXU6AdLWyMXHUeVCQoAAoQ0gAWcGBY2shcJBRUzsjMsBq62PoQhnzikmgycorKUJCh4VgsQSURURkUJgAqAO4YUFa29mhYFMVhES4Jnu70DF7sAkA). The second example generates: ```typescript (_c = (_b = perhaps.maybe) === null || _b === void 0 ? void 0 : _b.close) === null || _c === void 0 ? void 0 : _c.call(_b); ``` But could be optimized to: ```typescript (_b = perhaps.maybe) !== null && _b !== void 0 && (_c = _b.close) !== null && _c !== void 0 && _c.call(_b); ``` It's not a huge difference, but it saves 8 characters for each link in the chain. While the spec says something like: "_the expression short-circuits with a return value of undefined_", when the return value is meaningless, then only the "short-circuit" part is important.