We need a better error message for the use let/const/class in a Statement and not a StatementListItem

[Saam Barati]

i.e,
if (c)
   let/const/class F;

while (c)
   let/const/class F;

should have a better syntax error message.

[Daniel Ehrenberg]

Whenever you're editing this code, there's a case in this area that I believe should be allowed, but seems to throw a syntax error:

```
if (true) let: x()
```

or

```
with ({}) let: y()
```

When I run that in JSC, I get

SyntaxError: Unexpected token ':'. Parse error.

whereas in V8, ChakraCore and SpiderMonkey, let is permitted as a label.

[Caio Lima]

(In reply to comment #1)
> Whenever you're editing this code, there's a case in this area that I
> believe should be allowed, but seems to throw a syntax error:
> 
> ```
> if (true) let: x()
> ```
> 
> or
> 
> ```
> with ({}) let: y()
> ```
> 
> When I run that in JSC, I get
> 
> SyntaxError: Unexpected token ':'. Parse error.
> 
> whereas in V8, ChakraCore and SpiderMonkey, let is permitted as a label.

Daniel, we are solving this bug in https://bugs.webkit.org/show_bug.cgi?id=168684

Thank you for your report.

[Yusuke Suzuki]

*** This bug has been marked as a duplicate of bug 168684 ***