This is a workaround for a TS 3.9 regression https://github.com/microsoft/TypeScript/issues/38501 where the emitted `__exportStar` helpers have a missing semi-colon at the end of the unnamed function, when targetting UMD, and causes the following runtime error `Uncaught TypeError: (intermediate value)(…) is not a function`.
This is because the anonymous `__exportStar` function will be invoked with the function on the next like as the parameter which is subsequently invoking whatever was returned.
To get around this TS bug, add `importHelpers: true` in your tsconfig. This also, is recommanded to avoid multiple copies of the same helper being inlined, which might cause increase in bundle size.
PR Close#36989
bbd556ee9f