Gate test on unwinding support

Author: jieyouxu

Diff for: tests/ui/debuginfo/backtrace-line-tables-only.rs

@@ -6,6 +6,7 @@
 //@ ignore-android FIXME #17520
 //@ ignore-openbsd no support for libbacktrace without filename
 //@ ignore-fuchsia Backtraces not symbolized
+//@ needs-unwind
 //@ run-pass
 //@ compile-flags: -Cdebuginfo=line-tables-only -Cstrip=none
 #![feature(backtrace_frames)]