[perl #131508] [BUG] `state` with % is Sethash in whenever block ends up with a type object on second iteration

[Zoffix Znet via RT]

On Sun, 04 Jun 2017 07:12:25 -0700, c...@zoffix.com wrote:
> %goods here works as expected:
> 
> <Zoffix__> m: my %goods is SetHash; react whenever Supply.interval(.3)
> { $++ > 3 and done; dd %goods; %goods<foo>++; }
> <camelia> rakudo-moar 3755c0: OUTPUT:
> «SetHash.new()␤SetHash.new("foo")␤SetHash.new("foo")␤SetHash.new("foo")␤»
> 
> On second iteration ends up being a type object:
> 
> <Zoffix__> m: react whenever Supply.interval(.3) { state %goods is
> SetHash; $++ > 3 and done; dd %goods; %goods<foo>++; }
> <camelia> rakudo-moar 3755c0: OUTPUT: «SetHash.new()␤SetHash␤Tried to
> get the result of a broken Promise␤  in block <unit> at <tmp> line
> 1␤␤Original exception:␤    Cannot modify an immutable SetHash
> ((SetHash))␤      in block  at <tmp> line 1␤␤»

Another case:

```
<Zoffix_> m: <a b c>.grep: { (state %code-files is SetHash = <foo bar>); LEAVE 
dd %code-files; }
<camelia> rakudo-moar dd2c90192: OUTPUT: 
«SetHash.new("foo","bar")␤SetHash␤SetHash␤»
```