Rename RFC #1238 and add a note to RFC #769.

Author: nikomatsakis

text/0769-sound-generic-drop.md

@@ -2,6 +2,11 @@
 - RFC PR: [rust-lang/rfcs#769](https://github.com/rust-lang/rfcs/pull/769)
 - Rust Issue: [rust-lang/rust#8861](https://github.com/rust-lang/rust/issues/8861)
 
+# History
+
+2015.09.18 -- This RFC was partially superceded by RFC 1238, which
+removed the parametricity-based reasoning in favor of an attribute.
+
 # Summary
 
 Remove `#[unsafe_destructor]` from the Rust language.  Make it safe

text/0000-nonparametric-dropck.md renamed to text/1238-nonparametric-dropck.md

@@ -1,7 +1,7 @@
 - Feature Name: dropck_parametricity
 - Start Date: 2015-08-05
-- RFC PR: (leave this empty)
-- Rust Issue: (leave this empty)
+- RFC PR: https://github.com/rust-lang/rfcs/pull/1238/
+- Rust Issue: https://github.com/rust-lang/rust/issues/28498
 
 # Summary