Merge RFC #1211 (MIR)

Author: nikomatsakis

text/0000-mir.md renamed to text/1211-mir.md

@@ -1,7 +1,7 @@
 - Feature Name: N/A
 - Start Date: (fill me in with today's date, YYYY-MM-DD)
-- RFC PR: (leave this empty)
-- Rust Issue: (leave this empty)
+- RFC PR: [rust-lang/rfcs#1211](https://github.com/rust-lang/rfcs/pull/1211)
+- Rust Issue: [rust-lang/rust#27840](https://github.com/rust-lang/rust/issues/27840)
 
 # Summary