Rollup merge of rust-lang#104265 - faern:move-ipaddr-to-core, r=joshtriplett

Move IpAddr, SocketAddr and V4+V6 related types to `core`

Implements RFC rust-lang/rfcs#2832. The RFC has completed FCP with disposition merge, but is not yet merged.

Moves IP types to `core` as specified in the RFC.

The full list of moved types is: `IpAddr`, `Ipv4Addr`, `Ipv6Addr`, `SocketAddr`, `SocketAddrV4`, `SocketAddrV6`, `Ipv6MulticastScope` and `AddrParseError`.

Doing this move was one of the main driving arguments behind rust-lang#78802.

Author: Dylan-DPC

library/core/src/lib.rs

@@ -124,6 +124,8 @@
 #![feature(const_inherent_unchecked_arith)]
 #![feature(const_int_unchecked_arith)]
 #![feature(const_intrinsic_forget)]
+#![feature(const_ipv4)]
+#![feature(const_ipv6)]
 #![feature(const_likely)]
 #![feature(const_maybe_uninit_uninit_array)]
 #![feature(const_maybe_uninit_as_mut_ptr)]
@@ -179,6 +181,7 @@
 #![feature(const_slice_index)]
 #![feature(const_is_char_boundary)]
 #![feature(const_cstr_methods)]
+#![feature(ip)]
 #![feature(is_ascii_octdigit)]
 //
 // Language features:
@@ -348,6 +351,7 @@ pub mod cell;
 pub mod char;
 pub mod ffi;
 pub mod iter;
+pub mod net;
 pub mod option;
 pub mod panic;
 pub mod panicking;