[perl #131673] `is rw` on anon parameter causes "inconsistent bind result" error

[jn...@jnthn.net via RT]

On Wed, 28 Jun 2017 16:05:50 -0700, c...@zoffix.com wrote:
> Works as expected:
>     23:03               m: sub ($x is rw) {}(42)
>     camelia     rakudo-moar 2a8d1e: OUTPUT: «Parameter '$x' expected
> a writable container, but got Int value␤  in sub  at <tmp> line 1␤
> in block <unit> at <tmp> line 1␤␤»
> 
> Doesn't:
>     23:04               m: sub ($ is rw) {}(42)
>     23:04       camelia rakudo-moar 2a8d1e: OUTPUT: «Internal error:
> inconsistent bind result␤  in sub  at <tmp> line 1␤  in block
> <unit> at <tmp> line 1␤␤»

Fixed and tested in S06-traits/is-rw.t.