Declaring a var inside a catch block with the same name gives no error

Like #2185, but in catch blocks:

``` ts
try { }
catch (e) {
   let e;
   var e;
}
```

Section 13.14.1 of the ES6 spec says:

It is a Syntax Error if any element of the BoundNames of CatchParameter also occurs in the
LexicallyDeclaredNames of Block.

It is a Syntax Error if any element of the BoundNames of CatchParameter also occurs in the
VarDeclaredNames of Block
