Track the 'awaiter return' call stack use it to detect uncaught exceptions in async functions

runtime/vm/object.h

Index: runtime/vm/object.h
diff --git a/runtime/vm/object.h b/runtime/vm/object.h
index 9023b2f4256329a2b5df6364409b5cd61919d5b9..71b465ebb33bd25e800af4fd20516b0f869a31dd 100644
--- a/runtime/vm/object.h
+++ b/runtime/vm/object.h
@@ -4512,12 +4512,15 @@ class ExceptionHandlers : public Object {
   uword HandlerPCOffset(intptr_t try_index) const;
   intptr_t OuterTryIndex(intptr_t try_index) const;
   bool NeedsStackTrace(intptr_t try_index) const;
+  bool IsGenerated(intptr_t try_index) const;
 
   void SetHandlerInfo(intptr_t try_index,
                       intptr_t outer_try_index,
                       uword handler_pc_offset,
                       bool needs_stacktrace,
-                      bool has_catch_all) const;
+                      bool has_catch_all,
+                      TokenPosition token_pos,
+                      bool is_generated) const;
 
   RawArray* GetHandledTypes(intptr_t try_index) const;
   void SetHandledTypes(intptr_t try_index, const Array& handled_types) const;
@@ -4681,6 +4684,16 @@ class Code : public Object {
     StorePointer(&raw_ptr()->code_source_map_, code_source_map.raw());
   }
 
+  RawArray* await_token_positions() const {
+#if defined(DART_PRECOMPILED_RUNTIME)
+    return Array::null();
+#else
+    return raw_ptr()->await_token_positions_;
+#endif
+  }
+
+  void SetAwaitTokenPositions(const Array& await_token_positions) const;
+
   // Used during reloading (see object_reload.cc). Calls Reset on all ICDatas
   // that are embedded inside the Code object.
   void ResetICDatas(Zone* zone) const;