pattern matching on a reference to an enum results in an llvm broken module error

```
fn main() {
    let x = &Some(1);
    match x {
        &Some(_) => (),
        &None => (),
    }
}
```

Errors out with:

```
Basic Block in function '_ZN4main17_aaf9e7b54e88829e3_00E' does not have terminator!
label %8
LLVM ERROR: Broken module, no Basic Block terminator!
```
