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

runtime/vm/flow_graph_compiler.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef RUNTIME_VM_FLOW_GRAPH_COMPILER_H_
 #define RUNTIME_VM_FLOW_GRAPH_COMPILER_H_
 
 #include "vm/allocation.h"
 #include "vm/assembler.h"
 #include "vm/code_descriptors.h"
@@ skipping 473 matching lines @@
   // Returns true if there is a next block after the current one in
   // the block order and if it is the given block.
   bool CanFallThroughTo(BlockEntryInstr* block_entry) const;
 
   // Return true-, false- and fall-through label for a branch instruction.
   BranchLabels CreateBranchLabels(BranchInstr* branch) const;
 
   void AddExceptionHandler(intptr_t try_index,
                            intptr_t outer_try_index,
                            intptr_t pc_offset,
+                           TokenPosition token_pos,
+                           bool is_generated,
                            const Array& handler_types,
                            bool needs_stacktrace);
   void SetNeedsStackTrace(intptr_t try_index);
   void AddCurrentDescriptor(RawPcDescriptors::Kind kind,
                             intptr_t deopt_id,
                             TokenPosition token_pos);
   void AddDescriptor(RawPcDescriptors::Kind kind,
                      intptr_t pc_offset,
                      intptr_t deopt_id,
                      TokenPosition token_pos,
@@ skipping 297 matching lines @@
   ZoneGrowableArray<const ICData*>* deopt_id_to_ic_data_;
 
   Array& edge_counters_array_;
 
   DISALLOW_COPY_AND_ASSIGN(FlowGraphCompiler);
 };
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_FLOW_GRAPH_COMPILER_H_