Auto merge of #115694 - clarfonthey:std-hash-private, r=dtolnay

Add `std::hash::{DefaultHasher, RandomState}` exports (needs FCP)

This implements rust-lang/libs-team#267 to move the libstd hasher types to `std::hash` where they belong, instead of `std::collections::hash_map`.

<details><summary>The below no longer applies, but is kept for clarity.</summary>
This is a small refactor for #27242, which moves the definitions of `RandomState` and `DefaultHasher` into `std::hash`, but in a way that won't be noticed in the public API.

I've opened rust-lang/libs-team#267 as a formal ACP to move these directly into the root of `std::hash`, but for now, they're at least separated out from the collections code in a way that will make moving that around easier.

I decided to simply copy the rustdoc for `std::hash` from `core::hash` since I think it would be ideal for the two to diverge longer-term, especially if the ACP is accepted. However, I would be willing to factor them out into a common markdown document if that's preferred.
</details>

1 files changed, 2 insertions, 2 deletions

diff --git a/library/std/tests/common/mod.rs b/library/std/tests/common/mod.rs
index 358c2c3f9b2..1aad6549e76 100644
--- a/library/std/tests/common/mod.rs
+++ b/library/std/tests/common/mod.rs
@@ -1,17 +1,17 @@
 #![allow(unused)]
 
+use rand::RngCore;
 use std::env;
 use std::fs;
 use std::path::{Path, PathBuf};
 use std::thread;
-use rand::RngCore;
 
 /// Copied from `std::test_helpers::test_rng`, since these tests rely on the
 /// seed not being the same for every RNG invocation too.
 #[track_caller]
 pub(crate) fn test_rng() -> rand_xorshift::XorShiftRng {
     use core::hash::{BuildHasher, Hash, Hasher};
-    let mut hasher = std::collections::hash_map::RandomState::new().build_hasher();
+    let mut hasher = std::hash::RandomState::new().build_hasher();
     core::panic::Location::caller().hash(&mut hasher);
     let hc64 = hasher.finish();
     let seed_vec = hc64.to_le_bytes().into_iter().chain(0u8..8).collect::<Vec<u8>>();