Move memory handling into string, do not use compiler_builtins for memory handling

src/stdio/Cargo.toml

@@ -8,7 +8,6 @@ build = "build.rs"
 cbindgen = { path = "../../cbindgen" }
 
 [dependencies]
-compiler_builtins = { git = "https://github.com/rust-lang-nursery/compiler-builtins.git", default-features = false, features = ["mem"] }
 platform = { path = "../platform" }
 va_list = { path = "../../va_list", features = ["no_std"] }
 fcntl = { path = "../fcntl" }

src/stdio/src/lib.rs

@@ -1,9 +1,7 @@
 //! stdio implementation for Redox, following http://pubs.opengroup.org/onlinepubs/7908799/xsh/stdio.h.html
 
-#![feature(compiler_builtins_lib)]
 #![no_std]
 
-extern crate compiler_builtins;
 extern crate errno;
 extern crate fcntl;
 extern crate platform;