In TS we can re-export imports using statements of the form:
```
export * from 'some-import';
```
This is downleveled in UMD to:
```
function factory(exports, someImport) {
function __export(m) {
for (var p in m) if (!exports.hasOwnProperty(p)) exports[p] = m[p];
}
__export(someImport);
}
```
This commit adds support for this.
PR Close#34254
e9fb5fdb89