remove feature(convert_id) from lib{core,std}/lib.rs

Author: Centril

Diff for: src/libcore/lib.rs

@@ -83,7 +83,6 @@
 #![feature(const_fn)]
 #![feature(const_int_ops)]
 #![feature(const_fn_union)]
-#![feature(convert_id)]
 #![feature(custom_attribute)]
 #![feature(doc_cfg)]
 #![feature(doc_spotlight)]

Diff for: src/libstd/lib.rs

@@ -254,7 +254,6 @@
 #![feature(const_fn)]
 #![feature(const_int_ops)]
 #![feature(const_ip)]
-#![feature(convert_id)]
 #![feature(core_intrinsics)]
 #![feature(dropck_eyepatch)]
 #![feature(exact_size_is_empty)]