cast_ptr_alignment: move the .cast() check into a separate fn

Author: ada4a

clippy_lints/src/casts/cast_ptr_alignment.rs

@@ -18,7 +18,11 @@ pub(super) fn check(cx: &LateContext<'_>, expr: &Expr<'_>) {
             cx.typeck_results().expr_ty(expr),
         );
         lint_cast_ptr_alignment(cx, expr, cast_from, cast_to);
-    } else if let ExprKind::MethodCall(method_path, self_arg, [], _) = &expr.kind
+    }
+}
+
+pub(super) fn check_cast_method(cx: &LateContext<'_>, expr: &Expr<'_>) {
+    if let ExprKind::MethodCall(method_path, self_arg, [], _) = &expr.kind
         && method_path.ident.name == sym::cast
         && let Some(generic_args) = method_path.args
         && let [GenericArg::Type(cast_to)] = generic_args.args

clippy_lints/src/casts/mod.rs

@@ -915,6 +915,7 @@ impl<'tcx> LateLintPass<'tcx> for Casts {
             cast_slice_from_raw_parts::check_implicit_cast(cx, expr);
         }
         cast_ptr_alignment::check(cx, expr);
+        cast_ptr_alignment::check_cast_method(cx, expr);
         ptr_as_ptr::check(cx, expr, self.msrv);
         cast_slice_different_sizes::check(cx, expr, self.msrv);
         ptr_cast_constness::check_null_ptr_cast_method(cx, expr);