Add issue link at the top in files tests/ui/codegen/box-str-drop-glue.rs and tests/ui/drop/drop-noncopyable-raw-pointer.rs

tests/ui/codegen/box-str-drop-glue.rs

@@ -1,3 +1,4 @@
+//! regression test for <https://github.com/rust-lang/rust/issues/17734>
 //@ run-pass
 // Test that generating drop glue for Box<str> doesn't ICE
 

tests/ui/drop/drop-noncopyable-raw-pointer.rs

@@ -1,3 +1,4 @@
+//! regression test for <https://github.com/rust-lang/rust/issues/4735>
 //@ run-pass
 
 use std::mem::transmute;