In JS, typedef tags are not bound on non-expression statements

```js
/** @typedef {number} A */
var ok;
/** @typedef {number} B */
ok = 1; // also ok
/** @typedef {number} C not ok */
;
/** @typedef {number} D not ok */
if (ok) {
}
/** @type {[A, B, C, D]} */
var t = [1,2,3,4]
```

**Expected behavior:**
All of A, B, C, and D are type aliases for number.

**Actual behavior:**
Cannot find name 'C' and 'D'.