std: Stabilize TypeId and tweak BoxAny

This commit aims to stabilize the `TypeId` abstraction by moving it out of the
`intrinsics` module into the `any` module of the standard library. Specifically,

* `TypeId` is now defined at `std::any::TypeId`
* `TypeId::hash` has been removed in favor of an implementation of `Hash`.

This commit also performs a final pass over the `any` module, confirming the
following:

* `Any::get_type_id` remains unstable as *usage* of the `Any` trait will likely
  never require this, and the `Any` trait does not need to be implemented for
  any other types. As a result, this implementation detail can remain unstable
  until associated statics are implemented.
* `Any::downcast_ref` is now stable
* `Any::downcast_mut` is now stable
* `BoxAny` remains unstable. While a direct impl on `Box<Any>` is allowed today
  it does not allow downcasting of trait objects like `Box<Any + Send>` (those
  returned from `Thread::join`). This is covered by #18737.
* `BoxAny::downcast` is now stable.

1 files changed, 1 insertions, 1 deletions

diff --git a/src/libcoretest/intrinsics.rs b/src/libcoretest/intrinsics.rs
index bcf8a6a433b..b836f5f3f69 100644
--- a/src/libcoretest/intrinsics.rs
+++ b/src/libcoretest/intrinsics.rs
@@ -8,7 +8,7 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-use core::intrinsics::TypeId;
+use core::any::TypeId;
 
 #[test]
 fn test_typeid_sized_types() {