Auto merge of #83681 - jyn514:blanket-impls-tweaks, r=Aaron1011

rustdoc: Only look at blanket impls in `get_blanket_impls`

The idea here is that all the work in 16156fb278/compiler/rustc_middle/src/ty/trait_def.rs (L172-L186) doesn't matter for `get_blanket_impls` - Rustdoc will already pick up on those blocks when it documents the item.

compiler/rustc_middle/src/ty/trait_def.rs

@@ -69,6 +69,12 @@ pub struct TraitImpls {
     non_blanket_impls: FxHashMap<fast_reject::SimplifiedType, Vec<DefId>>,
 }
 
+impl TraitImpls {
+    pub fn blanket_impls(&self) -> &[DefId] {
+        self.blanket_impls.as_slice()
+    }
+}
+
 impl<'tcx> TraitDef {
     pub fn new(
         def_id: DefId,