Add isolate tag-profile and better handling of errors

runtime/vm/thread_interrupter.h

Index: runtime/vm/thread_interrupter.h
diff --git a/runtime/vm/thread_interrupter.h b/runtime/vm/thread_interrupter.h
index 30bc4a879f340250e8fbe12ad471ba65750e68ab..9ee100e33509e2e6fe44355a98ff55d86558e80f 100644
--- a/runtime/vm/thread_interrupter.h
+++ b/runtime/vm/thread_interrupter.h
@@ -61,6 +61,9 @@ class ThreadInterrupter : public AllStatic {
   // Get the current thread state. Will not create one if one doesn't exist.
   static InterruptableThreadState* CurrentThreadState();
 
+  // Interrupt a thread.
+  static void InterruptThread(InterruptableThreadState* thread_state);
+
  private:
   static const intptr_t kMaxThreads = 4096;
   static bool initialized_;
@@ -76,7 +79,6 @@ class ThreadInterrupter : public AllStatic {
 
   static void SetCurrentThreadState(InterruptableThreadState* state);
 
-  static void InterruptThread(InterruptableThreadState* thread_state);
   static void ThreadMain(uword parameters);
 
   static void InstallSignalHandler();