Rollup merge of rust-lang#146987 - hkBst:sort-params-1, r=nnethercote

impl Ord for params and use unstable sort

AFAICT we are only sorting to find duplicates, so unstable sort should work fine, and maybe is a tiny bit faster?

Author: Zalathar

compiler/rustc_hir_analysis/src/constrained_generic_params.rs

@@ -4,7 +4,7 @@ use rustc_middle::ty::{self, Ty, TyCtxt, TypeFoldable, TypeSuperVisitable, TypeV
 use rustc_span::Span;
 use tracing::debug;
 
-#[derive(Clone, PartialEq, Eq, Hash, Debug)]
+#[derive(Clone, Debug, PartialEq, Eq, Hash, PartialOrd, Ord)]
 pub(crate) struct Parameter(pub u32);
 
 impl From<ty::ParamTy> for Parameter {

compiler/rustc_hir_analysis/src/impl_wf_check/min_specialization.rs

@@ -275,7 +275,7 @@ fn check_duplicate_params<'tcx>(
     span: Span,
 ) -> Result<(), ErrorGuaranteed> {
     let mut base_params = cgp::parameters_for(tcx, parent_args, true);
-    base_params.sort_by_key(|param| param.0);
+    base_params.sort_unstable();
     if let (_, [duplicate, ..]) = base_params.partition_dedup() {
         let param = impl1_args[duplicate.0 as usize];
         return Err(tcx