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

runtime/vm/intermediate_language_dbc.cc

 // Copyright (c) 2016, 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.
 
 #include "vm/globals.h"  // Needed here to get TARGET_ARCH_DBC.
 #if defined(TARGET_ARCH_DBC)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/cpu.h"
@@ skipping 1131 matching lines @@
   if (compiler->is_optimizing()) {
     __ PopLocal(locs()->out(0).reg());
   }
 }
 
 
 EMIT_NATIVE_CODE(CatchBlockEntry, 0) {
   __ Bind(compiler->GetJumpLabel(this));
   compiler->AddExceptionHandler(catch_try_index(), try_index(),
                                 compiler->assembler()->CodeSize(),
+                                handler_token_pos(), is_generated(),
                                 catch_handler_types_, needs_stacktrace());
   // On lazy deoptimization we patch the optimized code here to enter the
   // deoptimization stub.
   const intptr_t deopt_id = Thread::ToDeoptAfter(GetDeoptId());
   if (compiler->is_optimizing()) {
     compiler->AddDeoptIndexAtCall(deopt_id);
   } else {
     compiler->AddCurrentDescriptor(RawPcDescriptors::kDeopt, deopt_id,
                                    TokenPosition::kNoSource);
   }
@@ skipping 847 matching lines @@
   }
   __ IfULe(length, index);
   compiler->EmitDeopt(deopt_id(), ICData::kDeoptCheckArrayBound,
                       (generalized_ ? ICData::kGeneralized : 0) |
                           (licm_hoisted_ ? ICData::kHoisted : 0));
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_DBC