Fix wildcard_enum_match_arm suggests wrongly with raw identifiers (rust-lang#15093)

Closes rust-lang#15091

The lack of ability to escape raw identifiers is a known issue of
Clippy. In this case, it can be avoided by snippet from the code.

changelog: [`wildcard_enum_match_arm`] fix wrong suggestions with raw
identifiers

Author: samueltardieu

clippy_lints/src/matches/match_wild_enum.rs

@@ -1,4 +1,5 @@
 use clippy_utils::diagnostics::{span_lint_and_sugg, span_lint_and_then};
+use clippy_utils::source::SpanRangeExt;
 use clippy_utils::ty::is_type_diagnostic_item;
 use clippy_utils::{is_refutable, peel_hir_pat_refs, recurse_or_patterns};
 use rustc_errors::Applicability;
@@ -116,11 +117,12 @@ pub(crate) fn check(cx: &LateContext<'_>, ex: &Expr<'_>, arms: &[Arm<'_>]) {
     let format_suggestion = |variant: &VariantDef| {
         format!(
             "{}{}{}{}",
-            if let Some(ident) = wildcard_ident {
-                format!("{} @ ", ident.name)
-            } else {
-                String::new()
-            },
+            wildcard_ident.map_or(String::new(), |ident| {
+                ident
+                    .span
+                    .get_source_text(cx)
+                    .map_or_else(|| format!("{} @ ", ident.name), |s| format!("{s} @ "))
+            }),
             if let CommonPrefixSearcher::Path(path_prefix) = path_prefix {
                 let mut s = String::new();
                 for seg in path_prefix {

tests/ui/wildcard_enum_match_arm.fixed

@@ -105,3 +105,17 @@ fn main() {
         }
     }
 }
+
+fn issue15091() {
+    enum Foo {
+        A,
+        B,
+        C,
+    }
+
+    match Foo::A {
+        Foo::A => {},
+        r#type @ Foo::B | r#type @ Foo::C => {},
+        //~^ wildcard_enum_match_arm
+    }
+}

tests/ui/wildcard_enum_match_arm.rs

@@ -105,3 +105,17 @@ fn main() {
         }
     }
 }
+
+fn issue15091() {
+    enum Foo {
+        A,
+        B,
+        C,
+    }
+
+    match Foo::A {
+        Foo::A => {},
+        r#type => {},
+        //~^ wildcard_enum_match_arm
+    }
+}

tests/ui/wildcard_enum_match_arm.stderr

@@ -40,5 +40,11 @@ error: wildcard match will also match any future added variants
 LL |             _ => (),
    |             ^ help: try: `Enum::B | Enum::__Private`
 
-error: aborting due to 6 previous errors
+error: wildcard match will also match any future added variants
+  --> tests/ui/wildcard_enum_match_arm.rs:118:9
+   |
+LL |         r#type => {},
+   |         ^^^^^^ help: try: `r#type @ Foo::B | r#type @ Foo::C`
+
+error: aborting due to 7 previous errors