Fix crash on aliased,exported @enum tag in jsdoc (#36996)

THe code to bind `@enum` and `@typedef` didn't handle the case that the
`@enum` was on a property assignment to an alias of module.exports.
Specifically, `x` needs to be correctly aliased to the file's symbol in
the example below:

```
var x = module.exports = {};
/** @enum {string} */
x.E = {
  A: "A"
};
```

tests/cases/conformance/jsdoc/exportedAliasedEnumTag.ts

@@ -0,0 +1,9 @@
+// @noemit: true
+// @allowjs: true
+// @filename: exportedAliasedEnumTag.js
+var middlewarify = module.exports = {};
+
+/** @enum */
+middlewarify.Type = {
+  BEFORE: 'before'
+};