swift234

[swiftc (50 vs. 5156)] Add crasher in ?

Add test case for crash triggered in `?`.

Current number of unresolved compiler crashers: 50 (5156 resolved)

Stack trace:

```
<unknown>:0: error: unable to execute command: Segmentation fault
<unknown>:0: error: compile command failed due to signal (use -v to see invocation)
```