Fix hints and clean-up obsolete comment syntax (TBR)

pkg/analysis_server/tool/instrumentation/page/stats_page.dart

Index: pkg/analysis_server/tool/instrumentation/page/stats_page.dart
diff --git a/pkg/analysis_server/tool/instrumentation/page/stats_page.dart b/pkg/analysis_server/tool/instrumentation/page/stats_page.dart
index d7bafb24a70d27aea15b6c0b3a29e3f3f0a1f78d..a8932a16920e07497e616be6a56107ea8a8738b8 100644
--- a/pkg/analysis_server/tool/instrumentation/page/stats_page.dart
+++ b/pkg/analysis_server/tool/instrumentation/page/stats_page.dart
@@ -89,7 +89,7 @@ class StatsPage extends PageWriter {
    * each kind.
    */
   void _processEntries(List<LogEntry> entries) {
-    void increment/*<K>*/(Map<dynamic/*=K*/, int> map, dynamic/*=K*/ key) {
+    void increment<K>(Map<K, int> map, K key) {
       map[key] = (map[key] ?? 0) + 1;
     }