remove const_fn feature gate

RalfJung · RalfJung · commit 92e392224a19 · 2021-05-09T14:29:31.000+02:00
diff --git a/std/src/lib.rs b/std/src/lib.rs
@@ -246,7 +246,6 @@
 #![feature(const_cstr_unchecked)]
 #![feature(const_fn_floating_point_arithmetic)]
 #![feature(const_fn_transmute)]
-#![feature(const_fn)]
 #![feature(const_fn_fn_ptr_basics)]
 #![feature(const_io_structs)]
 #![feature(const_ip)]
