Auto merge of #16222 - rosefromthedead:unresolved-assoc-item, r=Veykril

add unresolved-assoc-item assist

I tried to copy from private-assoc-item for this

crates/hir-ty/src/infer.rs

@@ -219,6 +219,9 @@ pub enum InferenceDiagnostic {
         field_with_same_name: Option<Ty>,
         assoc_func_with_same_name: Option<AssocItemId>,
     },
+    UnresolvedAssocItem {
+        id: ExprOrPatId,
+    },
     // FIXME: This should be emitted in body lowering
     BreakOutsideOfLoop {
         expr: ExprId,

crates/hir-ty/src/infer/path.rs

@@ -340,6 +340,9 @@ impl InferenceContext<'_> {
             },
         );
         let res = res.or(not_visible);
+        if res.is_none() {
+            self.push_diagnostic(InferenceDiagnostic::UnresolvedAssocItem { id });
+        }
         let (item, visible) = res?;
 
         let (def, container) = match item {