Move small-base-lexing out of 0000

Author: alexcrichton

text/0000-small-base-lexing.md renamed to text/0879-small-base-lexing.md

@@ -1,7 +1,7 @@
 - Feature Name: stable, it only restricts the language
 - Start Date: 2015-02-17
-- RFC PR: (leave this empty)
-- Rust Issue: (leave this empty)
+- RFC PR: [rust-lang/rfcs#879](https://github.com/rust-lang/rfcs/pull/879)
+- Rust Issue: [rust-lang/rust#23872](https://github.com/rust-lang/rust/pull/23872)
 
 # Summary