Undo drop-locations.rs change

The compiler crashed in CI when compiling drop-locations.rs, so
restore the ignore-test marker there.

Author: tromey

src/test/debuginfo/drop-locations.rs

@@ -1,6 +1,6 @@
 // ignore-windows
 // ignore-android
-// ignore-lldb // Test temporarily ignored due to debuginfo tests being disabled, see PR 47155
+// ignore-test // Test temporarily ignored due to debuginfo tests being disabled, see PR 47155
 // min-lldb-version: 310
 
 #![allow(unused)]