FS0748 error "This construct may only be used in computation expresions" reported for 'return' when it is not true

I knew I was testing potentially invalid code, but I was surprised to see the error:


Or in text for googleability:

> FS0748: This construct may only be used within computation expressions. To return a value from an ordinaty function simply write the expression without 'return'.

### Repro steps

Use something like `return 1, return 2` at the end of any computation expression.

### Expected behavior

Some syntax error, but not the one mentioned above.

### Actual behavior

Error FS0748 as mentioned is reported, but the error says I am not inside a computation expression, while I am.

### Known workarounds

Don't listen to the error, but fix your code ;).

### Related information

As an aside (as always): it would be interesting to here thoughts on allowing `return x, return y`, but I'm not sure if we can get the behavior defined cleanly. My expectation would be that it would return a tuple of two instances of the computation expression.

* Seen in VS 15.6 and 15.7, but likely the same in any recent version.