Don't idle tick isolates paused before start or exit

runtime/vm/isolate.cc

Index: runtime/vm/isolate.cc
diff --git a/runtime/vm/isolate.cc b/runtime/vm/isolate.cc
index 003c59d849655993ab0a7cff2f4069ba3d6d2f03..2a9f10e56afb72662a0b29fbdee9367d42589502 100644
--- a/runtime/vm/isolate.cc
+++ b/runtime/vm/isolate.cc
@@ -1015,6 +1015,12 @@ intptr_t Isolate::ProfileInterrupt() {
     // Profiler blocked for this isolate.
     return 0;
   }
+  if (message_handler()->paused_on_start() ||
+      message_handler()->paused_on_exit() ||
+      debugger()->IsPaused()) {
+    // Paused at start / exit / breakpoint. Don't tick.
+    return 0;
+  }
   InterruptableThreadState* state = thread_state();
   if (state == NULL) {
     // Isolate is not scheduled on a thread.