Add needs-unwind to the test as suggested.

Author: khuey

tests/ui/panics/location-detail-unwrap-multiline.rs

@@ -2,6 +2,7 @@
 //@ compile-flags: -Cstrip=none -Cdebuginfo=line-tables-only -Copt-level=0
 //@ exec-env:RUST_BACKTRACE=1
 //@ regex-error-pattern: location-detail-unwrap-multiline\.rs:9:10\n
+//@ needs-unwind
 
 fn main() {
     let opt: Option<u32> = None;