remove explicit if_let and tuple_indexing feature enables as they now trigger warnings

Author: Pedro Larroy

src/libcollections/lib.rs

@@ -24,7 +24,7 @@
 #![allow(unknown_features)]
 #![feature(macro_rules, default_type_params, phase, globs)]
 #![feature(unsafe_destructor, import_shadowing, slicing_syntax)]
-#![feature(tuple_indexing, unboxed_closures)]
+#![feature(unboxed_closures)]
 #![no_std]
 
 #[phase(plugin, link)] extern crate core;

src/librustc_borrowck/lib.rs

@@ -16,8 +16,8 @@
       html_favicon_url = "http://www.rust-lang.org/favicon.ico",
       html_root_url = "http://doc.rust-lang.org/nightly/")]
 
-#![feature(default_type_params, globs, if_let, import_shadowing, macro_rules, phase, quote)]
-#![feature(slicing_syntax, tuple_indexing, unsafe_destructor)]
+#![feature(default_type_params, globs, import_shadowing, macro_rules, phase, quote)]
+#![feature(slicing_syntax, unsafe_destructor)]
 #![feature(rustc_diagnostic_macros)]
 #![feature(unboxed_closures)]
 #![allow(non_camel_case_types)]