Add stub entry to unstable book for needs_drop

Gankra · Gankra · commit 1f01b09ddcd5 · 2017-05-20T19:27:31.000-04:00
diff --git a/src/doc/unstable-book/src/library-features/needs-drop.md b/src/doc/unstable-book/src/library-features/needs-drop.md
@@ -0,0 +1,7 @@
+# `needs_drop`
+
+The tracking issue for this feature is: [#41890]
+
+[#41890]: https://github.com/rust-lang/rust/issues/41890
+
+------------------------
