Add raw identifier in a typo suggestion

Author: linyihai

compiler/rustc_resolve/src/diagnostics.rs

@@ -1617,7 +1617,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             let post = format!(", consider renaming `{}` into `{snippet}`", suggestion.candidate);
             (span, snippet, post)
         } else {
-            (span, suggestion.candidate.to_string(), String::new())
+            (span, suggestion.candidate.to_ident_string(), String::new())
         };
         let msg = match suggestion.target {
             SuggestionTarget::SimilarlyNamed => format!(

tests/ui/span/suggestion-raw-68962.rs

@@ -0,0 +1,11 @@
+fn r#fn() {}
+
+fn main() {
+    let r#final = 1;
+
+    // Should correctly suggest variable defined using raw identifier.
+    fina; //~ ERROR cannot find value
+
+    // Should correctly suggest function defined using raw identifier.
+    f(); //~ ERROR cannot find function
+}

tests/ui/span/suggestion-raw-68962.stderr

@@ -0,0 +1,18 @@
+error[E0425]: cannot find value `fina` in this scope
+  --> $DIR/suggestion-raw-68962.rs:7:5
+   |
+LL |     fina;
+   |     ^^^^ help: a local variable with a similar name exists: `r#final`
+
+error[E0425]: cannot find function `f` in this scope
+  --> $DIR/suggestion-raw-68962.rs:10:5
+   |
+LL | fn r#fn() {}
+   | --------- similarly named function `r#fn` defined here
+...
+LL |     f();
+   |     ^ help: a function with a similar name exists: `r#fn`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0425`.