Change lint to use const sym

Author: camsteffen

clippy_lints/src/utils/internal_lints.rs

@@ -225,7 +225,7 @@ declare_clippy_lint! {
     ///
     /// Good:
     /// ```rust,ignore
-    /// utils::is_type_diagnostic_item(cx, ty, sym!(vec_type))
+    /// utils::is_type_diagnostic_item(cx, ty, sym::vec_type)
     /// ```
     pub MATCH_TYPE_ON_DIAGNOSTIC_ITEM,
     internal,
@@ -724,7 +724,7 @@ impl<'tcx> LateLintPass<'tcx> for MatchTypeOnDiagItem {
                     expr.span,
                     "usage of `utils::match_type()` on a type diagnostic item",
                     "try",
-                    format!("utils::is_type_diagnostic_item({}, {}, sym!({}))", cx_snippet, ty_snippet, item_name),
+                    format!("utils::is_type_diagnostic_item({}, {}, sym::{})", cx_snippet, ty_snippet, item_name),
                     Applicability::MaybeIncorrect,
                 );
             }

tests/ui/match_type_on_diag_item.stderr

@@ -2,7 +2,7 @@ error: usage of `utils::match_type()` on a type diagnostic item
   --> $DIR/match_type_on_diag_item.rs:41:17
    |
 LL |         let _ = match_type(cx, ty, &paths::VEC);
-   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `utils::is_type_diagnostic_item(cx, ty, sym!(vec_type))`
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `utils::is_type_diagnostic_item(cx, ty, sym::vec_type)`
    |
 note: the lint level is defined here
   --> $DIR/match_type_on_diag_item.rs:1:9
@@ -15,19 +15,19 @@ error: usage of `utils::match_type()` on a type diagnostic item
   --> $DIR/match_type_on_diag_item.rs:42:17
    |
 LL |         let _ = match_type(cx, ty, &OPTION);
-   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `utils::is_type_diagnostic_item(cx, ty, sym!(option_type))`
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `utils::is_type_diagnostic_item(cx, ty, sym::option_type)`
 
 error: usage of `utils::match_type()` on a type diagnostic item
   --> $DIR/match_type_on_diag_item.rs:43:17
    |
 LL |         let _ = match_type(cx, ty, &["core", "result", "Result"]);
-   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `utils::is_type_diagnostic_item(cx, ty, sym!(result_type))`
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `utils::is_type_diagnostic_item(cx, ty, sym::result_type)`
 
 error: usage of `utils::match_type()` on a type diagnostic item
   --> $DIR/match_type_on_diag_item.rs:46:17
    |
 LL |         let _ = utils::match_type(cx, ty, rc_path);
-   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `utils::is_type_diagnostic_item(cx, ty, sym!(Rc))`
+   |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `utils::is_type_diagnostic_item(cx, ty, sym::Rc)`
 
 error: aborting due to 4 previous errors