Auto merge of #85892 - tmiasko:i, r=oli-obk

Miscellaneous inlining improvements

compiler/rustc_hir/src/definitions.rs

@@ -305,6 +305,7 @@ impl Definitions {
         self.table.index_to_key.len()
     }
 
+    #[inline]
     pub fn def_key(&self, id: LocalDefId) -> DefKey {
         self.table.def_key(id.local_def_index)
     }

compiler/rustc_hir/src/hir.rs

@@ -2488,6 +2488,7 @@ pub enum FnRetTy<'hir> {
 }
 
 impl FnRetTy<'_> {
+    #[inline]
     pub fn span(&self) -> Span {
         match *self {
             Self::DefaultReturn(span) => span,