Use VM tag in profile and add stack trace trie

runtime/bin/vmservice/client/lib/src/service/cache.dart

Index: runtime/bin/vmservice/client/lib/src/service/cache.dart
diff --git a/runtime/bin/vmservice/client/lib/src/service/cache.dart b/runtime/bin/vmservice/client/lib/src/service/cache.dart
index 39e001d87a16731116108470b84886d9fbbb6d41..a1d8fe4382fac6755f3383dabae644f7d0e5a2aa 100644
--- a/runtime/bin/vmservice/client/lib/src/service/cache.dart
+++ b/runtime/bin/vmservice/client/lib/src/service/cache.dart
@@ -113,6 +113,13 @@ class CodeCache extends ServiceObjectCache<Code> {
     return codeList;
   }
 
+  static const TAG_ROOT_ID = 'code/tag-0';
+
+  /// Returns the Code object for the root tag.
+  Code tagRoot() {
+    return _cache[TAG_ROOT_ID];
+  }
+
   void _resetProfileData() {
     _cache.forEach((k, Code code) {
       code.resetProfileData();
@@ -154,6 +161,7 @@ class FunctionCache extends ServiceObjectCache<ServiceMap> {
                  r'^functions/collected-.+|'
                  r'^functions/reused-.+|'
                  r'^functions/stub-.+|'
+                 r'^functions/tag-.+|'
                  r'^classes/\d+/functions/.+|'
                  r'^classes/\d+/closures/.+|'
                  r'^classes/\d+/implicit_closures/.+|'