don't intern defined symbol, remove mentions of 'debug_tuple'

Author: y21

clippy_lints/src/missing_fields_in_debug.rs

@@ -136,7 +136,7 @@ fn as_field_call<'tcx>(
     if let ExprKind::MethodCall(path, recv, [debug_field, _], _) = &expr.kind
         && let recv_ty = typeck_results.expr_ty(recv).peel_refs()
         && match_type(cx, recv_ty, &paths::DEBUG_STRUCT)
-        && path.ident.name == sym!(field)
+        && path.ident.name == sym::field
         && let ExprKind::Lit(lit) = &debug_field.kind
         && let LitKind::Str(sym, ..) = lit.node
     {
@@ -194,8 +194,7 @@ fn check_struct<'tcx>(
 /// the item is an enum.
 ///
 /// Currently, only simple cases are detected where the user
-/// matches on `self` and calls `debug_struct` or `debug_tuple`
-/// inside of the arms
+/// matches on `self` and calls `debug_struct` inside of the arms
 fn check_enum<'tcx>(
     cx: &LateContext<'tcx>,
     typeck_results: &TypeckResults<'tcx>,