Crash on cyclic struct type

Hi,

I accidentally defined a cyclic struct, and llc 6.0.0 crashes. I would
have expected a meaningful error message, rather than a crash.
Minimal example attached.

Has this been fixed already? If not, can I test this against the latest
LLVM version without locally installing/compiling the whole thing, or
should I file a bug report against LLVM-6.0.0?

I just quickly checked, crashes the same way on trunk.

-Eli