[perl #131384] .open(:enc) on file with unicode leads to MoarVM panic: MVM_nfg_get_synthetic_info called with out-of-range synthetic

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

On Sat, 27 May 2017 08:01:00 -0700, c...@zoffix.com wrote:
> <Zoffix___> c: HEAD with "/tmp/foo2121".IO { .spurt: "fo♥o"; with
> .open(:enc<ascii>) { say .slurp } }
> <committable6> Zoffix___, ¦HEAD(0c5fe56): «MoarVM panic:
> MVM_nfg_get_synthetic_info called with out-of-range synthetic «exit
> code = 1»»
> 
> This is not the result of encoding refactor; still exists in 2017.05:
> <Zoffix___> c: 2017.05 with "/tmp/foo2121".IO { .spurt: "fo♥o"; with
> .open(:enc<ascii>) { say .slurp } }
> <committable6> Zoffix___, ¦2017.05: «MoarVM panic:
> MVM_nfg_get_synthetic_info called with out-of-range synthetic «exit
> code = 1»»

Fixed (now it gives a normal decoding exception) and tested in 
S32-io/io-handle.t.