No comment preservation for parenthesized expressions

[DanielRosenwasser]

@evmar ran into issues where generating a JSDoc comment for a type assertion for Closure did not get preserved.

Neither

var x = (/** @type {Foo.Bar} */ y);

nor

var x = /** @type {Foo.Bar} */ (y);

have their comments preserved, though I'm not sure which is more common.

[weswigham]

@DanielRosenwasser

var x = /** @type {Foo.Bar} */y;

is also unpreserved. It's not unique to parenthesized expressions.

[mprobst]

Also happens for dotted expressions:

let x = /** @type {string} */ foo.bar;

[olemartinorg]

Not sure if related, but it also happens for regular comments when they appear before a }:

// Comment
let a = 5;
// Another comment
if (a === 5) { 
    alert('hello world');
    // Third comment
}

Compiles to:

// Comment
var a = 5;
// Another comment
if (a === 5) {
    alert('hello world');
}